1
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Koo J, Kim W, Jhun BH, Park S, Song D, You Y, Lee HG. Halogen Atom Transfer-Induced Homolysis of C-F Bonds by the Excited-State Boryl Radical. J Am Chem Soc 2024; 146:22874-22880. [PMID: 39093360 DOI: 10.1021/jacs.4c06337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
A novel reactivity toward C-F bond functionalization has been developed, which could be designated as fluorine atom transfer (FAT). A photoexcited state of an N-heterocyclic carbene-ligated boryl radical exhibits a transcendent reactivity, capable of activating chemically inert carbon-fluorine bonds through homolysis. Combined experimental and computational studies suggest that the ligated boryl radical species directly abstracts a fluorine atom from the organofluoride substrates to provide valuable carbon-centered radicals.
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Affiliation(s)
- Jangwoo Koo
- Department of Chemistry, College of Natural Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Weonjeong Kim
- Department of Chemistry, College of Natural Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Byung Hak Jhun
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Subin Park
- Department of Chemistry, College of Natural Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Dayoon Song
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Youngmin You
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Hong Geun Lee
- Department of Chemistry, College of Natural Science, Seoul National University, Seoul 08826, Republic of Korea
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2
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Buettner CS, Stavagna C, Tilby MJ, Górski B, Douglas JJ, Yasukawa N, Leonori D. Synthesis and Suzuki-Miyaura Cross-Coupling of Alkyl Amine-Boranes. A Boryl Radical-Enabled Strategy. J Am Chem Soc 2024. [PMID: 39137918 DOI: 10.1021/jacs.4c07767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Alkyl organoborons are powerful materials for the construction of C(sp3)-C(sp2) bonds, predominantly via Suzuki-Miyaura cross-coupling. These species are generally assembled using 2-electron processes that harness the ability of boron reagents to act as both electrophiles and nucleophiles. Herein, we demonstrate an alternative borylation strategy based on the reactivity of amine-ligated boryl radicals. This process features the use of a carboxylic acid containing amine-ligated borane that acts as boryl radical precursor for photoredox oxidation and decarboxylation. The resulting amine-ligated boryl radical undergoes facile addition to styrenes and imines through radical-polar crossover manifolds. This delivers a new class of sp3-organoborons that are stable solids and do not undergo protodeboronation. These novel materials include unprotected α-amino derivatives that are generally unstable. Crucially, these aliphatic organoboron species can be directly engaged in Suzuki-Miyaura cross-couplings with structurally complex aryl halides. Preliminary studies suggest that they enable slow-release of the corresponding and often difficult to handle alkyl boronic acids.
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Affiliation(s)
- Cornelia S Buettner
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| | - Chiara Stavagna
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| | - Michael J Tilby
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Bartosz Górski
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - James J Douglas
- Early Chemical Development, Pharmaceutical Sciences, R&D, AstraZeneca, Macclesfield SK10 2NA, United Kingdom
| | - Naoki Yasukawa
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan
| | - Daniele Leonori
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
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3
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Duan Y, Zheng Z, Yu Z, Sun S, Lin B, Liu X, Liu P. Catalyst-Free α- trans-Selective Hydroboration and ( E)-Selective Deuterated Semihydrogenation of Alkynyl Sulfones. J Org Chem 2024; 89:8326-8333. [PMID: 38817078 DOI: 10.1021/acs.joc.3c02833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
Here, we present a straightforward α-trans-selective hydroboration of alkynyl sulfones with NHC-boranes without the need for a catalyst. This reaction is compatible with a wide range of substrates for efficiently producing structurally diverse α-borylated vinyl sulfones in satisfactory yields. The hydride transfer from NHC-borane 2a to alkynyl triflone 1b is studied by density functional theory (DFT) calculations for trans-hydroboration. Moreover, a regiodivergent deuterated semihydrogenation of alkynyl triflones has also been developed using D2O as the deuterium source. A variety of diversity-oriented D-containing vinyl triflones were prepared in good to excellent yields with excellent deuterium incorporation ratios. Synthetic manipulations of the deuterated products are achieved for the conversion into valuable deuterated molecules, indicating the utility of this protocol.
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Affiliation(s)
- Yunnan Duan
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China
| | - Zhouqing Zheng
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China
| | - Zhiwei Yu
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Shitao Sun
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Bin Lin
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Xiaozu Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi 563000, China
| | - Peijun Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi 563000, China
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4
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Zhang Q, Xu W, Liu Q, Xia C, Shao Q, Ma L, Wu M. Diastereoselective dearomatization of indoles via photocatalytic hydroboration on hydramine-functionalized carbon nitride. Nat Commun 2024; 15:4371. [PMID: 38778032 PMCID: PMC11111752 DOI: 10.1038/s41467-024-48769-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
A protocol for trans-hydroboration of indole derivatives using heterogeneous photocatalysis with NHC-borane has been developed, addressing a persistent challenge in organic synthesis. The protocol, leveraging high crystalline vacancy-engineered polymeric carbon nitride as a catalyst, enables diastereoselective synthesis, expanding substrate scope and complementing existing methods. The approach emphasizes eco-friendliness, cost-effectiveness, and scalability, making it suitable for industrial applications, particularly in renewable energy contexts. The catalyst's superior performance, attributed to its rich carbon-vacancies and well-ordered structure, surpasses more expensive homogeneous alternatives, enhancing viability for large-scale use. This innovation holds promise for synthesizing bioactive compounds and materials relevant to medicinal chemistry and beyond.
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Affiliation(s)
- Qiao Zhang
- College of New Energy, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao, P. R. China
| | - Wengang Xu
- College of New Energy, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao, P. R. China.
| | - Qiong Liu
- Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology (China), Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center, Guangzhou), Guangzhou, P. R. China.
| | - Congjian Xia
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, P. R. China
| | - Qi Shao
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, P. R. China
| | - Lishuang Ma
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, P. R. China
| | - Mingbo Wu
- College of New Energy, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao, P. R. China.
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, P. R. China.
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5
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Phang YL, Jin JK, Zhang FL, Wang YF. Radical hydroboration for the synthesis of organoboron compounds. Chem Commun (Camb) 2024; 60:4275-4289. [PMID: 38566567 DOI: 10.1039/d4cc00398e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Organoboron compounds demonstrate diverse applications in the fields of organic synthesis, materials science, and medicinal chemistry. Compared to the conventional hydroboration reaction, radical hydroboration serves as an alternative approach for the synthesis of organoborons via different mechanisms. In radical hydroboration, a boryl radical is initially generated from homolytic cleavage of a B-H or a B-B bond, which is then added to an unsaturated double bond to deliver a carbon radical. Subsequent hydrogen atom transfer or reduction of the carbon radical to form a carbanion followed by protonation gave the final product. Over the past few years, numerous efforts have been made for efficient synthesis of boryl radicals and the expansion of substrate scope of the radical hydroboration reaction. Here, we discuss the recent advancement of radical hydroboration and its associated mechanisms. Numerous radical hydroboration strategies employing N-heterocyclic carbene borane, bis(pinacolato)diboron and pinacolborane as the boron source were illustrated. Thermochemical, photochemical and electrochemical strategies for the generation of boryl radicals were also discussed in detail.
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Affiliation(s)
- Yee Lin Phang
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Ji-Kang Jin
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Feng-Lian Zhang
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Yi-Feng Wang
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
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6
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Das A, Elvers BJ, Chrysochos N, Uddin SI, Gangber T, Krummenacher I, Borah D, Mishra A, Shanmugam M, Yildiz CB, Braunschweig H, Schulzke C, Jana A. Dianionic and Neutral Diboron-Centered Classical Diradicaloids. J Am Chem Soc 2024; 146:9004-9011. [PMID: 38502925 DOI: 10.1021/jacs.3c13310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Herein, we report the syntheses and electronic structures of crystalline dianionic as well as neutral diboron-centered classical diradicaloids as boron analogues of classical Thiele, Chichibabin, and Müller (this only for dianionic diradicaloids!) hydrocarbons. These are based on borane radical anion and NHC-stabilized boryl radical spin carriers, respectively. All these dianionic diboron-centered diradicaloids exhibit triplet population at room temperature regardless of the π-conjugated spacer: p-phenylene, p,p'-biphenylene, or p,p″-terphenylene. In the case of neutral diboron-centered diradicaloids, the employed π-conjugated spacer plays a crucial role for the triplet population at room temperature: EPR inactive for p-phenylene vs EPR active for p,p'-biphenylene. The findings emphasize the importance of the spin carriers for the resulting ground-state: borane radical anion vs NHC-stabilized boryl radical along with the pivotal role of the π-conjugated spacer as spin-coupler between two spins. Notably, 100 years (a century) after the first report by Krause of the triphenyl borane radical-anion, being isoelectronic to the triphenylmethyl radical, we convey borane radical anion-based diradicaloids. Furthermore, while donor-stabilized boryl radicals were introduced in the 1980s by Giles and Roberts, said concept is herewith being extended to NHC-stabilized boryl radical-based diradicaloids.
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Affiliation(s)
- Ayan Das
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Greifswald D-17489, Germany
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Sk Imraj Uddin
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Tejaswinee Gangber
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Dipanti Borah
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
| | - Anshika Mishra
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Maheswaran Shanmugam
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
| | - Cem B Yildiz
- Department of Aromatic and Medicinal Plants, Aksaray University, Aksaray 68100, Turkey
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Greifswald D-17489, Germany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
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7
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Guo X, Lin Z. Boryls, their compounds and reactivity: a structure and bonding perspective. Chem Sci 2024; 15:3060-3070. [PMID: 38425516 PMCID: PMC10901493 DOI: 10.1039/d3sc06864a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/01/2024] [Indexed: 03/02/2024] Open
Abstract
Boryls and their compounds are important due to their diverse range of applications in the fields of materials science and catalysis. They are an integral part of boron chemistry, which has attracted tremendous research interest over the past few decades. In this perspective, we provide an in-depth analysis of the reaction chemistry of boryl compounds from a structure and bonding perspective. We discuss the reactivity of boryls in various transition metal complexes and diborane(4) compounds towards different substrate molecules, with a focus on their nucleophilic and electrophilic properties in various reaction processes. Additionally, we briefly discuss the reactivity of boryl radicals. Our analysis sheds new light on the unique properties of boryls and their potential for catalytic applications.
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Affiliation(s)
- Xueying Guo
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong
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8
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Kundu G, Amrutha PR, Tothadi S, Sen SS. Access to NHC-Boryl Mono- and Bis-Selenide and Utility as Mild Selenium Transfer Reagent Including to the C-F Bond. Chemistry 2024; 30:e202302984. [PMID: 37943498 DOI: 10.1002/chem.202302984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 11/10/2023]
Abstract
Reactions of 5-SIDipp ⋅ BH3 (5-SIDipp=1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene) (1) with diphenyldiselenide provide access to 5-SIDipp-boryl mono- (5-SIDipp ⋅ BH2 SePh) (2) and bis-selenide (5-SIDipp ⋅ BH(SePh)2 ) (3). The facile cleavage of the B-Se bond makes 2 a neutral source of selenium nucleophiles in substitutions reactions with benzyl bromides, and provide access to the corresponding selenoethers. The direct transformations of one of the C(sp2 )-F bonds of C5 F5 N and C6 F5 CF3 to C-Se bonds have also been achieved by the use of 2 without employing transition-metal catalysts. While it was previously established that C6 F6 could undergo complete defluoroselenation under harsh conditions, we successfully achieved partial defluorination of C6 F6 by employing 2 as a mild selenide transfer reagent. During the formation of C-Se bonds through the cleavage of C-F bonds, the potential by-product NHC ⋅ BH2 F undergoes ring expansion of the NHC, leading to the formation of the six-membered diaazafluoroborinane (7).
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Affiliation(s)
- Gargi Kundu
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, 411008, Pashan, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, India
| | - P R Amrutha
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, 411008, Pashan, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, India
| | - Srinu Tothadi
- Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, India
- Analytical and Environmental Sciences Division and Centralized Instrumentation Facility, CSIR-Central Salt and Marine Chemicals Research Institute, Gijubhai Badheka Marg, 364002, Bhavnagar, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, 411008, Pashan, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, India
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9
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Merschel A, Vishnevskiy YV, Neumann B, Stammler HG, Ghadwal RS. Ring-Opening of 1,3-Imidazole Based Mesoionic Carbenes (iMICs) and Ring-Closing Clicks: Facile Access to iMIC-Compounds. Chemistry 2024; 30:e202303652. [PMID: 37937442 DOI: 10.1002/chem.202303652] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/09/2023]
Abstract
Herein, ring-opening of mesoionic carbenes (iMICs) (iMIC=[ArC{N(Dipp)}2 C(SiMe3 )C:) (Dipp=2,6-iPr2 C6 H3 , Ar=Ph, 4-Me2 NC6 H4 or 4-PhC6 H4 ) based on an 1,3-imidazole scaffold to yield N-ethynylformimidamide (eFIM) derivatives as crystalline solids (eFIM={(Dipp)N=C(Ar)N(Dipp)}C≡CSiMe3 ) is reported. eFIMs are thermally stable under inert gas atmosphere and show moderate air stability (t1/2= 3 h for Ar=Ph). eFIMs are excellent surrogates of iMICs, which generally have a limited shelf-life, and readily undergo ring-closing click reactions with a variety of main-group as well as transition metal Lewis acids to form hitherto challenging iMIC-compounds in good to excellent yields. In addition to the relevance of eFIMs in the synthesis of iMIC-compounds, quantification of the stereoelectronic properties of a representative iMIC (Ar=Ph) by experimental and theoretical methods suggests remarkably σ-donor property and steric profile of these new ligand sets.
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Affiliation(s)
- Arne Merschel
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, D-33615, Bielefeld, Germany
| | - Yury V Vishnevskiy
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, D-33615, Bielefeld, Germany
| | - Beate Neumann
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, D-33615, Bielefeld, Germany
| | - Hans-Georg Stammler
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, D-33615, Bielefeld, Germany
| | - Rajendra S Ghadwal
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, D-33615, Bielefeld, Germany
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10
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Wu Z, Vlaming R, Donohoe M, Pratt DA. Interrupted Homolytic Substitution Enables Organoboron Compounds to Inhibit Radical Chain Reactions Rather than Initiate Them. J Am Chem Soc 2024; 146:1153-1166. [PMID: 38156607 DOI: 10.1021/jacs.3c12438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The reactions of organoboranes with peroxyl radicals are key to their use as radical initiators for a vast array of radical chain reactions, particularly at low temperatures where high stereoselectivity or regioselectivity is desired. Whereas these reactions generally proceed via concerted homolytic substitution (SH2) mechanisms, organoboranes that bear groups that can stabilize tetracoordinate boron radical "ate" complexes (e.g., catecholboranes) undergo this reaction via a stepwise addition/fragmentation sequence and serve as useful stoichiometric alkyl radical precursors. Here we show that arylboronic esters and amides derived from catecholborane and diaminonaphthaleneborane, respectively, are potent radical-trapping antioxidants (RTAs). Mechanistic studies reveal that this is because the radical "ate" complexes derived from peroxyl radical addition to boron are sufficiently persistent to trap another radical in an interrupted SH2 reaction. Remarkably, the reactivity of these organoboranes as inhibitors of autoxidation was shown to translate from simple hydrocarbons to the phospholipids of biological membranes such that they can inhibit ferroptosis, the cell death modality driven by lipid autoxidation and relevant in neurodegeneration and other major pathologies. The unique mechanism of these organoboranes is one of only a handful of RTA mechanisms that are not based on H-atom transfer processes and provide a new dimension to boron chemistry and its applications.
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Affiliation(s)
- Zijun Wu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Robynne Vlaming
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Michael Donohoe
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Derek A Pratt
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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11
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Wang Y, Tran PM, Lahm ME, Wei P, Adams ER, Schaefer HF, Robinson GH. From Carbene-Dithiolene Zwitterion Mediated B-H Bond Activation to BH 3·SMe 2-Assisted Boron-Boron Bond Formation. Organometallics 2023; 42:3328-3333. [PMID: 38098647 PMCID: PMC10716900 DOI: 10.1021/acs.organomet.3c00361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Indexed: 12/17/2023]
Abstract
The 1:1 reaction of the carbene-stabilized dithiolene zwitterion 1 with BH3·SMe2 gave the dithiolene-based hydroborane 2 and the doubly hydrogen-capped CAAC species 3 via hydride-coupled reverse electron transfer processes. The mechanism of this transformation was probed computationally using density functional theory. The subsequent 2:1 reaction of 2 with 1 resulted in 4 and 3, suggesting that 1 can mediate the B-H bond activation not only for BH3 but also for monohydroboranes. In the presence of BH3·SMe2, 2 was unexpectedly converted to the corresponding diborane(4) complex 5 through a dehydrocoupling reaction at an elevated temperature.
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Affiliation(s)
- Yuzhong Wang
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Phuong M. Tran
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Mitchell E. Lahm
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Pingrong Wei
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Earle R. Adams
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Henry F. Schaefer
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Gregory H. Robinson
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
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12
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Lou X, Lin J, Kwok CY, Lyu H. Stereoselective Unsymmetrical 1,1-Diborylation of Alkynes with a Neutral sp 2 -sp 3 Diboron Reagent. Angew Chem Int Ed Engl 2023; 62:e202312633. [PMID: 37822069 DOI: 10.1002/anie.202312633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 10/13/2023]
Abstract
The incorporation of two distinct boryl groups at the same carbon center in organic molecules has attracted growing research interest due to its potential for facilitating controlled, precise synthesis through stepwise dual carbon-boron bond transformations. Here we report a method to access unsymmetrical 1,1-diborylalkene (UDBA) stereoselectively via the reaction of readily available alkynes with a neutral sp2 -sp3 diboron reagent (NHC)BH2 -Bpin (NHC=N-heterocyclic carbene). Attributing to the chemically easily distinguishable nature of the sp2 and sp3 boryl moieties, controllable stepwise derivatization of the resultant UDBAs is realized. This process leads to various multifunctionalized olefins and organoborons, such as acylboranes, which are difficult to prepare by other methods.
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Affiliation(s)
- Xiangyu Lou
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Jiaxin Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Chun Yin Kwok
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Hairong Lyu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
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13
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Röther A, Farmer JC, Portwich FL, Görls H, Kretschmer R. Anion-Dependent Reactivity of Mono- and Dinuclear Boron Cations. Chemistry 2023; 29:e202302544. [PMID: 37641815 DOI: 10.1002/chem.202302544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
The dinuclear bis(N-heterocyclic carbene) borane adduct 2 rapidly reacts with tritylium salts at room temperature but the outcome is strongly impacted by the respective counter-ion. Using tritylium tetrakis(perfluoro-tert-butoxy)aluminate affords - depending on the solvent - either the bis(boronium) ion 4 or the hydride-bridged dication 5. In case of tritylium hexafluorophosphate, however, H/F exchange occurs between boron and phosphorus yielding the dinuclear BF3 adduct 3 along with phosphorus dihydride trifluoride. H/F exchange also takes place when using the mononuclear N-heterocyclic carbene BH3 adduct 6 and hence provides a facile route to PH2 F3 , which is usually synthesized in more complex reaction sequences regularly involving toxic hydrogen fluoride. DFT calculations shed light on the H/F exchange between the borenium ion and the [PF6 ]- counter-ion and the computed mechanism features only small barriers in line with the experimental observations.
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Affiliation(s)
- Alexander Röther
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - James C Farmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Flavio L Portwich
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
- Institute of Chemistry, Chemnitz University of Technology, Straße der Nationen 62, 09111, Chemnitz, Germany
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14
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Werner L, Hagn J, Walpuski J, Radius U. Aluminum(III) Cations [(NHC) ⋅ AlMes 2 ] + : Synthesis, Characterization, and Application in FLP-Chemistry. Angew Chem Int Ed Engl 2023:e202312111. [PMID: 37877231 DOI: 10.1002/anie.202312111] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 10/26/2023]
Abstract
The three-coordinate aluminum cations ligated by N-heterocyclic carbenes (NHCs) [(NHC) ⋅ AlMes2 ]+ [B(C6 F5 )4 ]- (NHC=IMeMe 4, IiPrMe 5, IiPr 6, Mes=2,4,6-trimethylphenyl) were prepared via hydride abstraction of the alanes (NHC) ⋅ AlHMes2 (NHC=IMeMe 1, IiPrMe 2, IiPr 3) using [Ph3 C]+ [B(C6 F5 )4 ]- in toluene as hydride acceptor. If this reaction was performed in diethyl ether, the corresponding four-coordinate aluminum etherate cations [(NHC) ⋅ AlMes2 (OEt2 )]+ [B(C6 F5 )4 ]- 7-9 (NHC=IMeMe 7, IiPrMe 8, IiPr 9) were isolated. According to a theoretical and experimental assessment of the Lewis-acidity of the [(IMeMe ) ⋅ AlMes2 ]+ cation is the acidity larger than that of B(C6 F5 )3 and of similar magnitude as reported for Al(C6 F5 )3 . The reaction of [(IMeMe ) ⋅ AlMes2 ]+ [B(C6 F5 )4 ]- 4 with the sterically less demanding, basic phosphine PMe3 afforded a mixed NHC/phosphine stabilized cation [(IMeMe ) ⋅ AlMes2 (PMe3 )]+ [B(C6 F5 )4 ]- 10. Equimolar mixtures of 4 and the sterically more demanding PCy3 gave a frustrated Lewis-pair (FLP), i.e., [(IMeMe ) ⋅ AlMes2 ]+ [B(C6 F5 )4 ]- /PCy3 FLP-11, which reacts with small molecules such as CO2 , ethene, and 2-butyne.
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Affiliation(s)
- Luis Werner
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Julika Hagn
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Janis Walpuski
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Udo Radius
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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15
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Xie F, Mao Z, Curran DP, Liang H, Dai W. Facile Borylation of Alkenes, Alkynes, Imines, Arenes and Heteroarenes with N-Heterocyclic Carbene-Boranes and a Heterogeneous Semiconductor Photocatalyst. Angew Chem Int Ed Engl 2023; 62:e202306846. [PMID: 37555790 DOI: 10.1002/anie.202306846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/10/2023]
Abstract
Although the development of radical chain and photocatalytic borylation reactions using N-heterocyclic carbene (NHC)-borane as boron source is remarkable, the persistent problems, including the use of hazardous and high-energy radical initiators or the recyclability and photostability issues of soluble homogeneous photocatalysts, still leave great room for further development in a sustainable manner. Herein, we report a conceptually different approach toward highly functionalized organoborane synthesis by using recoverable ultrathin cadmium sulfide (CdS) nanosheets as a heterogeneous photocatalyst, and a general and mild borylation platform that enables regioselective borylation of a wide variety of alkenes (arylethenes, trifluoromethylalkenes, α,β-unsaturated carbonyl compounds and nitriles), alkynes, imines and electron-poor aromatic rings with NHC-borane as boryl radical precursor. Mechanistic studies and density functional theory (DFT) calculations reveal that both photogenerated electrons and holes on the CdS fully perform their own roles, thereby resulting in enhancement of photocatalytic activity and stability of CdS.
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Affiliation(s)
- Fukai Xie
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Zhan Mao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Dennis P Curran
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15208, USA
| | - Hongliang Liang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Wen Dai
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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16
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Hippolyte L, Sadek O, Ba Sowid S, Porcheron A, Bridonneau N, Blanchard S, Desage-El Murr M, Gatineau D, Gimbert Y, Mercier D, Marcus P, Chauvier C, Chanéac C, Ribot F, Fensterbank L. N-Heterocyclic Carbene Boranes: Dual Reagents for the Synthesis of Gold Nanoparticles. Chemistry 2023; 29:e202301610. [PMID: 37265455 DOI: 10.1002/chem.202301610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/03/2023]
Abstract
N-Heterocyclic carbenes (NHCs) have drawn considerable interest in the field of nanomaterials chemistry as highly stabilizing ligands enabling the formation of strong and covalent carbon-metal bonds. Applied to gold nanoparticles synthesis, the most common strategy consists of the reduction of a preformed NHC-AuI complex with a large excess of a reducing agent that makes the particle size difficult to control. In this paper, we report the straightforward synthesis of NHC-coated gold nanoparticles (NHC-AuNPs) by treating a commercially available gold(I) precursor with an easy-to-synthesize NHC-BH3 reagent. The latter acts as both the reducing agent and the source of surface ligands operating under mild conditions. Mechanistic studies including NMR spectroscopy and mass spectrometry demonstrate that the reduction of gold(I) generates NHC-BH2 Cl as a by-product. This strategy gives efficient control over the nucleation and growth of gold particles by varying the NHC-borane/gold(I) ratio, allowing unparalleled particle size variation over the range of 4.9±0.9 to 10.0±2.7 nm. Our strategy also allows an unprecedented precise and controlled seeded growth of gold nanoparticles. In addition, the as-prepared NHC-AuNPs exhibit narrow size distributions without the need for extensive purification or size-selectivity techniques, and are stable over months.
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Affiliation(s)
- Laura Hippolyte
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), 75252, Paris Cedex 05, France
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
| | - Omar Sadek
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
| | - Salem Ba Sowid
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), 75252, Paris Cedex 05, France
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
| | - Alexandre Porcheron
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), 75252, Paris Cedex 05, France
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
| | - Nathalie Bridonneau
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), 75252, Paris Cedex 05, France
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), 91400, Orsay Cedex, France
| | - Sébastien Blanchard
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
| | - Marine Desage-El Murr
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
| | - David Gatineau
- Département de Chimie Moléculaire (UMR CNRS 5250), Université Grenoble Alpes, 38050, Grenoble, France
| | - Yves Gimbert
- Département de Chimie Moléculaire (UMR CNRS 5250), Université Grenoble Alpes, 38050, Grenoble, France
| | - Dimitri Mercier
- PSL Research University, CNRS - Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), Physical Chemistry of Surfaces Research Group, 75005, Paris, France
| | - Philippe Marcus
- PSL Research University, CNRS - Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), Physical Chemistry of Surfaces Research Group, 75005, Paris, France
| | - Clément Chauvier
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
| | - Corinne Chanéac
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), 75252, Paris Cedex 05, France
| | - François Ribot
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), 75252, Paris Cedex 05, France
| | - Louis Fensterbank
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 75252, Paris Cedex 05, France
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17
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Li FX, Wang X, Lin J, Lou X, Ouyang J, Hu G, Quan Y. Selective multifunctionalization of N-heterocyclic carbene boranes via the intermediacy of boron-centered radicals. Chem Sci 2023; 14:6341-6347. [PMID: 37325159 PMCID: PMC10266453 DOI: 10.1039/d3sc01132a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/17/2023] [Indexed: 06/17/2023] Open
Abstract
The selective difunctionalization of N-heterocyclic carbene (NHC) boranes with alkenes has been achieved via decatungstate and thiol synergistic catalysis. The catalytic system also allows stepwise trifunctionalization, leading to complex NHC boranes with three different functional groups which are challenging to prepare by other methods. The strong hydrogen-abstracting ability of the excited decatungstate enables the generation of boryl radicals from mono- and di-substituted boranes for realizing borane multifunctionalization. This proof-of-principle research provides a new chance for fabricating unsymmetrical boranes and developing boron-atom-economic synthesis.
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Affiliation(s)
- Feng-Xing Li
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong SAR China
| | - Xinmou Wang
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong SAR China
| | - Jiaxin Lin
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong SAR China
| | - Xiangyu Lou
- Department of Chemistry, The Chinese University of Hong Kong Shatin, N.T. Hong Kong SAR China
| | - Jing Ouyang
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong SAR China
| | - Guanwen Hu
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong SAR China
| | - Yangjian Quan
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong SAR China
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18
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Nazish M, Legendre CM, Ding Y, Schluschaß B, Schwederski B, Herbst-Irmer R, Parvathy P, Parameswaran P, Stalke D, Kaim W, Roesky HW. A Neutral Borylene and its Conversion to a Radical by Selective Hydrogen Transfer. Inorg Chem 2023. [PMID: 37294916 DOI: 10.1021/acs.inorgchem.3c00211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A successful selective reduction of X2B-Tip (Tip = 1,3,5-iPr3-C6H2, X = I, Br) with KC8 and Mg metal, respectively, in the presence of a hybrid ligand (C6H4(PPh2)LSi) leads to a stable low-valent five-membered ring as a boryl radical [C6H4(PPh2)LSiBTip][Br] (1) and neutral borylene [C6H4(PPh2)LSiBTip] (2). Compound 2 reacts with 1,4-cyclohexadiene, resulting in hydrogen abstraction to afford the radical [C6H4(PPh2)LSiB(H)Tip] (3). Quantum chemical studies reveal that compound 1 is a B-centered radical, and compound 2 is a phosphane and silylene stabilized neutral borylene in a trigonal planar environment, whereas compound 3 is an amidinate-centered radical. Although compounds 1 and 2 are stabilized by hyperconjugation and π-conjugation, they display high H-abstraction energy and basicity, respectively.
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Affiliation(s)
- Mohd Nazish
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Christina M Legendre
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Yi Ding
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Bastian Schluschaß
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Brigitte Schwederski
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Regine Herbst-Irmer
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Parameswaran Parvathy
- Department of Chemistry, National Institute of Technology Calicut, Kerala 673601, India
| | - Pattiyil Parameswaran
- Department of Chemistry, National Institute of Technology Calicut, Kerala 673601, India
| | - Dietmar Stalke
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Herbert W Roesky
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
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19
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Kundu G, Amrutha PR, Raj KV, Tothadi S, Vanka K, Sen SS. Taming the parent oxoborane. Chem Sci 2023; 14:5894-5898. [PMID: 37293651 PMCID: PMC10246693 DOI: 10.1039/d3sc01544k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 04/25/2023] [Indexed: 06/10/2023] Open
Abstract
Despite recent advancements in the chemistry of multiply bound boron compounds, the laboratory isolation of the parent oxoborane moiety, HBO has long remained an unsolved and well-recognized challenge. The reaction of 6-SIDipp·BH3 [6-SIDipp = 1,3-di(2,6-diisopropylphenyl)tetrahydropyrimidine-2-ylidene] with GaCl3 afforded an unusual boron-gallium 3c-2e compound (1). The addition of water to 1 resulted in the release of H2 and the formation of a rare acid stabilized neutral parent oxoborane, LB(H)[double bond, length as m-dash]O (2). Crystallographic and density functional theory (DFT) analyses support the presence of a terminal B[double bond, length as m-dash]O double bond. Subsequent addition of another equivalent of water molecule led to hydrolysis of the B-H bond to the B-OH bond, but the 'B[double bond, length as m-dash]O' moiety remained intact, resulting in the formation of the hydroxy oxoborane compound (3), which can be classified as a monomeric form of metaboric acid.
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Affiliation(s)
- Gargi Kundu
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pashan Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
| | - P R Amrutha
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pashan Pune 411008 India
| | - K Vipin Raj
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pashan Pune 411008 India
| | - Srinu Tothadi
- Analytical and Environmental Sciences Division and Centralized Instrumentation Facility, CSIR-Central Salt and Marine Chemicals Research Institute Gijubhai Badheka Marg Bhavnagar-364002 India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pashan Pune 411008 India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pashan Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
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20
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Ju MY, Fan ZH, Ma Y, Jing Y, Chen XM, Chen X. Syntheses, Structures, and Reactivities of N-Heterocyclic Carbene-Coordinated Aminoborane Complexes. Inorg Chem 2023. [PMID: 37224452 DOI: 10.1021/acs.inorgchem.3c00930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Recent research has attracted considerable attention toward N-heterocyclic carbene-coordinated boranes (NHC-borane) and their B-substituted derivatives because of their unique characteristics. In the present work, we focused on the syntheses, structures, and reactivities of such types of amine complexes, [NHC·BH2NH3]X ((NHC = IPr (1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and IMe (1,3-dimethylimidazol-2-ylidene); X = Cl, I, OTf). We have developed a synthetic method to access NHC·BH2NH2 through the reaction of NaH with [IPr·BH2NH3]I, which was synthesized by the reaction of IPr·BH2I with NH3. As a Lewis base, NHC·BH2NH2 could further react with HCl or HOTf to produce the corresponding salts of [IPr·BH2NH3]+. IPr·BH2NH2BH2X (X = Cl, I) were synthesized by the reaction of HCl/I2 with IPr·BH2NH2BH3 and then converted to [IPr·BH2NH2BH2·IPr]X (X = Cl, I) by reacting with IPr. The IMe-coordinated boranes reacted quite similarly. The preliminary results revealed that the introduction of the NHC molecule has a considerable impact on the solubility and reactivities of aminoboranes.
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Affiliation(s)
- Ming-Yue Ju
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Zi-Heng Fan
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yubin Ma
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yi Jing
- College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Xi-Meng Chen
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xuenian Chen
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
- College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China
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21
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Hu C, Mena J, Alabugin IV. Design principles of the use of alkynes in radical cascades. Nat Rev Chem 2023:10.1038/s41570-023-00479-w. [PMID: 37117812 DOI: 10.1038/s41570-023-00479-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2023] [Indexed: 03/30/2023]
Abstract
One of the simplest organic functional groups, the alkyne, offers a broad canvas for the design of cascade transformations in which up to three new bonds can be added to each of the two sterically unencumbered, energy-rich carbon atoms. However, kinetic protection provided by strong π-orbital overlap makes the design of new alkyne transformations a stereoelectronic puzzle, especially on multifunctional substrates. This Review describes the electronic properties contributing to the unique utility of alkynes in radical cascades. We describe how to control the selectivity of alkyne activation by various methods, from dynamic covalent chemistry with kinetic self-sorting to disappearing directing groups. Additionally, we demonstrate how the selection of reactive intermediates directly influences the propagation and termination of the cascade. Diverging from a common departure point, a carefully planned reaction route can allow access to a variety of products.
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22
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Boyet M, Chabaud L, Pucheault M. Recent Advances in the Synthesis of Borinic Acid Derivatives. Molecules 2023; 28:molecules28062660. [PMID: 36985634 PMCID: PMC10057197 DOI: 10.3390/molecules28062660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 03/18/2023] Open
Abstract
Borinic acids [R2B(OH)] and their chelate derivatives are a subclass of organoborane compounds used in cross-coupling reactions, catalysis, medicinal chemistry, polymer or optoelectronics materials. In this paper, we review the recent advances in the synthesis of diarylborinic acids and their four-coordinated analogs. The main strategies to build up borinic acids rely either on the addition of organometallic reagents to boranes (B(OR)3, BX3, aminoborane, arylboronic esters) or the reaction of triarylboranes with a ligand (diol, amino alcohol, etc.). After general practical considerations of borinic acids, an overview of the main synthetic methods, their scope and limitations is provided. We also discuss some mechanistic aspects.
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23
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Li X, Zhang G, Song Q. Recent advances in the construction of tetracoordinate boron compounds. Chem Commun (Camb) 2023; 59:3812-3820. [PMID: 36883254 DOI: 10.1039/d2cc06982b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Tetracoordinate boron compounds are a highly important class of molecules, which are the key intermediates in many organoboron-related chemical transformations and have unique luminescence properties. However, the synthesis of tetracoordinate boron compounds has never been reviewed. In this highlight, we summarize recent progress on the construction of racemic and chiral tetracoordinate borons, and hope to provide ideas for the assembly of them in more efficient ways, especially for the construction of boron-stereogenic compounds.
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Affiliation(s)
- Xue Li
- Institute of Next Generation Matter Transformation, College of Material Sciences Engineering at Huaqiao University, 668 Jimei Blvd, Xiamen, Fujian, 361021, China.
| | - Guan Zhang
- Key Laboratory of Molecule Synthesis and Function Discovery, Fujian Province University, College of Chemistry at Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Qiuling Song
- Institute of Next Generation Matter Transformation, College of Material Sciences Engineering at Huaqiao University, 668 Jimei Blvd, Xiamen, Fujian, 361021, China. .,Key Laboratory of Molecule Synthesis and Function Discovery, Fujian Province University, College of Chemistry at Fuzhou University, Fuzhou, Fujian, 350108, China.,School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, China
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24
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Coordination Versatility of NHC-metal Topologies in Asymmetric Catalysis: Synthetic Insights and Recent Trends. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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25
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Yu T, Yang J, Wang Z, Ding Z, Xu M, Wen J, Xu L, Li P. Selective [2σ + 2σ] Cycloaddition Enabled by Boronyl Radical Catalysis: Synthesis of Highly Substituted Bicyclo[3.1.1]heptanes. J Am Chem Soc 2023; 145:4304-4310. [PMID: 36763965 DOI: 10.1021/jacs.2c13740] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
In contrast to the traditional and widely-used cycloaddition reactions involving at least a π bond component, a [2σ + 2σ] radical cycloaddition between bicyclo[1.1.0]butanes (BCBs) and cyclopropyl ketones has been developed to provide a modular, concise, and atom-economical synthetic route to substituted bicyclo[3.1.1]heptane (BCH) derivatives that are 3D bioisosteres of benzenes and core skeleton of a number of terpene natural products. The reaction was catalyzed by a combination of simple tetraalkoxydiboron(4) compound B2pin2 and 3-pentyl isonicotinate. The broad substrate scope has been demonstrated by synthesizing a series of new highly functionalized BCHs with up to six substituents on the core with up to 99% isolated yield. Computational mechanistic investigations supported a pyridine-assisted boronyl radical catalytic cycle.
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Affiliation(s)
- Tao Yu
- Frontier Institute of Science and Technology and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710054, China
| | - Jinbo Yang
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Zhijun Wang
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Zhengwei Ding
- Department of Medicinal Chemistry, School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Ming Xu
- Frontier Institute of Science and Technology and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710054, China
| | - Jingru Wen
- Frontier Institute of Science and Technology and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710054, China
| | - Liang Xu
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Pengfei Li
- Frontier Institute of Science and Technology and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710054, China
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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26
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Wang Z, Chen J, Lin Z, Quan Y. Photoinduced Dehydrogenative Borylation via Dihydrogen Bond Bridged Electron Donor and Acceptor Complexes. Chemistry 2023; 29:e202203053. [PMID: 36396602 DOI: 10.1002/chem.202203053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/17/2022] [Accepted: 11/17/2022] [Indexed: 11/19/2022]
Abstract
Air-stable amine- and phosphine-boranes are discovered as donors to integrate with pyridinium acceptor for generating photoactive electron-donor-acceptor (EDA) complexes. Experimental results and DFT calculations suggest a dihydrogen bond bridging the donor and acceptor. Irradiating the EDA complex enables an intra-complex single electron transfer to give a boron-centered radical for dehydrogenative borylation with no need of external photosensitizer and radical initiator. The deprotonation of Wheland-like radical intermediate rather than its generation is believed to determine the good ortho-selectivity based on DFT calculations. A variety of α-borylated pyridine derivatives have been readily synthesized with good functional group tolerance.
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Affiliation(s)
- Zhiyong Wang
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| | - Jiaxin Chen
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| | - Yangjian Quan
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
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27
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Metal-Free One-Pot Multi-Functionalization of Unsaturated Compounds with Interelement Compounds by Radical Process. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020787. [PMID: 36677845 PMCID: PMC9861539 DOI: 10.3390/molecules28020787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/14/2023]
Abstract
In recent years, the importance of "environmentally friendly manufacturing" has been increasing toward the establishment of a resource-recycling society. In organic synthesis, as well, it is becoming increasingly important to develop new synthetic strategies with resource conservation and the recycling of elemental resources in mind, rather than just only synthesis. Many studies on the construction of frameworks of functional molecules using ionic reactions and transition-metal-catalyzed reactions have been reported, but most of them have focused on the formation of carbon-carbon bonds. However, it is essential to introduce appropriate functional groups at appropriate positions in molecules in order for the molecules to express their functions, and furthermore, the highly selective preparation of multiple functional groups is considered important for the creation of new functional molecules. In this review, we focus on radical reactions with high functional group selectivity and overview the recent progress in practical methods for the simultaneous introduction of multiple functional groups and propose future synthetic strategies that emphasize the recycling of elemental resources and environmental friendliness.
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28
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Li DC, Zeng JH, Yang YH, Zhan ZP. Transition metal-free radical trans-hydroboration of alkynes with NHC-boranes via visible-light photoredox catalysis. Org Chem Front 2023. [DOI: 10.1039/d3qo00135k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Visible-light-induced 4-CzIPN-catalyzed trans-hydroboration of alkynes with NHC-boranes to generate diverse (E)-alkenylboranes with high selectivity.
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29
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Choi W, Kim M, Lee K, Park S, Hong S. C4-Selective C-H Borylation of Pyridinium Derivatives Driven by Electron Donor-Acceptor Complexes. Org Lett 2022; 24:9452-9457. [PMID: 36524721 DOI: 10.1021/acs.orglett.2c03882] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The photoinduced C4-selective C-H borylation of pyridines was achieved using electron donor-acceptor complexes derived from a Lewis base and N-amidopyridinium salts under external oxidant- and photocatalyst-free conditions. Notably, the nucleophilic character of phosphite-ligated boryl radicals enables addition of a radical to position C4 of pyridinium salts to afford C4-borylated heteroarenes that are otherwise difficult to obtain. This approach provides a versatile platform for the installation of both phosphite- and amine-coordinated boron groups on a series of pyridines under mild conditions, demonstrating excellent C4-positional selectivity for the pyridine scaffolds.
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Affiliation(s)
- Wonjun Choi
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Minseok Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Kangjae Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Seongjin Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Sungwoo Hong
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Korea
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30
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Wan T, Capaldo L, Ravelli D, Vitullo W, de Zwart FJ, de Bruin B, Noël T. Photoinduced Halogen-Atom Transfer by N-Heterocyclic Carbene-Ligated Boryl Radicals for C(sp 3)-C(sp 3) Bond Formation. J Am Chem Soc 2022; 145:991-999. [PMID: 36583709 PMCID: PMC9853867 DOI: 10.1021/jacs.2c10444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Herein, we present a comprehensive study on the use of N-heterocyclic carbene (NHC)-ligated boryl radicals to enable C(sp3)-C(sp3) bond formation under visible-light irradiation via Halogen-Atom Transfer (XAT). The methodology relies on the use of an acridinium dye to generate the boron-centered radicals from the corresponding NHC-ligated boranes via single-electron transfer (SET) and deprotonation. These boryl radicals subsequently engage with alkyl halides in an XAT step, delivering the desired nucleophilic alkyl radicals. The present XAT strategy is very mild and accommodates a broad scope of alkyl halides, including medicinally relevant compounds and biologically active molecules. The key role of NHC-ligated boryl radicals in the operative reaction mechanism has been elucidated through a combination of experimental, spectroscopic, and computational studies. This methodology stands as a significant advancement in the chemistry of NHC-ligated boryl radicals, which had long been restricted to radical reductions, enabling C-C bond formation under visible-light photoredox conditions.
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Affiliation(s)
- Ting Wan
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Luca Capaldo
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Davide Ravelli
- PhotoGreen
Lab, Department of Chemistry, University
of Pavia, viale Taramelli 12, 27100 Pavia, Italy
| | - Walter Vitullo
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Felix J. de Zwart
- Homogeneous,
Supramolecular and Bio-inspired Catalysis Group (HomKat), van’t
Hoff Institute for Molecular Sciences (HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Bas de Bruin
- Homogeneous,
Supramolecular and Bio-inspired Catalysis Group (HomKat), van’t
Hoff Institute for Molecular Sciences (HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Timothy Noël
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands,E-mail:
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31
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Tian X, Ding YH. Free and Complexed Fluoropentazoles: Anomalous Ring Charge and Appreciable Kinetic Stability. J Phys Chem Lett 2022; 13:10567-10574. [PMID: 36343011 DOI: 10.1021/acs.jpclett.2c02008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Fluoronitrogens are strongly related to high-energy density materials. Fluoropentazole (cyclo-FN5) with hitherto the highest N/F ratio at ambient pressure belongs to the family of well-known and 119-year-old pentazoles. Due to the presence of the overwhelmingly electronegative F element, cyclo-FN5 is the only pentazole to date that contains a cationic N5 ring. However, also due to F's large electronegativity, the reported ring-destruction barrier of cyclo-FN5 is nearly the lowest (6.7 kcal/mol), which has made its synthesis and characterization quite difficult. Here, cyclo-FN5 was re-predicted to bear an almost doubled ring-destruction barrier (∼12-14 kcal/mol) at the CBS-QB3, G4, W1BD, CCSD(T)/CBS//CCSD/cc-pVTZ, and CCSD(T)/CBS//CCSD(T)/aug-cc-pVTZ levels. Promisingly, upon further complexation with Lewis acid(s), the ring-destruction barrier of cyclo-FN5 might reach 23 kcal/mol, which is comparable to that of the well-known and already synthesized arylpentazoles (∼20 kcal/mol), and the positive charge on the N5 ring can be increased to 0.66 |e|.
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Affiliation(s)
- Xiao Tian
- Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou Key Lab of Advanced Energy Storage and Conversion, Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, P. R. China
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, P. R. China
- School of Mathematics and Science, Hebei GEO University, Shijiazhuang 050031, P. R. China
| | - Yi-Hong Ding
- Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou Key Lab of Advanced Energy Storage and Conversion, Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, P. R. China
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, P. R. China
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32
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Panferova LI, Zubkov MO, Kosobokov MD, Dilman AD. Light-Promoted Dearylation of Perfluorinated Aryl Sulfides with N-Heterocyclic Carbene–Borane. Org Lett 2022; 24:8559-8563. [DOI: 10.1021/acs.orglett.2c03585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Liubov I. Panferova
- N.D. Zelinsky Institute of Organic Chemistry, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Mikhail O. Zubkov
- N.D. Zelinsky Institute of Organic Chemistry, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Mikhail D. Kosobokov
- N.D. Zelinsky Institute of Organic Chemistry, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Alexander D. Dilman
- N.D. Zelinsky Institute of Organic Chemistry, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
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33
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Kundu G, Balayan K, Tothadi S, Sen SS. Six-Membered Saturated NHC-Stabilized Borenium Cations: Isolation of a Cationic Analogue of Borinic Acid. Inorg Chem 2022; 61:12991-12997. [PMID: 35930736 DOI: 10.1021/acs.inorgchem.2c00611] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of six-membered saturated NHC [1,3-di(2,6-diisopropylphenyl) tetrahydropyrimidine-2-ylidene; henceforth abbreviated as 6-SIDipp] with PhBCl2 yields a Lewis base adduct, 6-SIDipp·PhBCl2 (1), which readily undergoes nucleophilic substitution reaction with AgNO3, leading to the single (2) and double (3) substitution of both chlorides with ONO2 moieties at the boron atom. The reaction of 1 with 1 equiv of AlCl3 resulted in a borenium cation of composition [6-SIDipp·B(Ph)Cl]+ (4) with AlCl4- as the counteranion. Although borenium cations with different substituents on boron have been reported, a structurally characterized phenylchloroborenium cation remains unknown. Similarly, the reaction of 1 with triflic acid provides the first representative of a new class of borenium cations bearing one hydroxyl and one phenyl group on boron (5), a cationic analogue of borinic acid.
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Affiliation(s)
- Gargi Kundu
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Kajal Balayan
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Srinu Tothadi
- Analytical and Environmental Sciences Division and Centralized Instrumentation Facility, CSIR-Central Salt and Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavnagar 364002, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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34
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Banerjee S, Vanka K. Computational insights into hydroboration with acyclic α-Borylamido-germylene and stannylene catalysts: Cooperative dual catalysis the key to system efficiency. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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35
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Abstract
In this paper, we have used a saturated five-membered N-Heterocyclic carbene (5SIDipp = 1,3-bis-(2,6-diisopropylphenyl)imidazolin-2-ylidine) for the synthesis of SNHC-haloboranes adducts and their further nucleophilic substitutions to put unusual functional groups at the central boron atom. The reaction of 5-SIDipp with RBCl2 yields Lewis-base adducts, 5-SIDipp·RBCl2 [R = H (1), Ph (2)]. The hydrolysis of 1 gives the NHC stabilized boric acid, 5-SIDipp·B(OH)3 (3), selectively. Replacement of chlorine atoms from 1 and 2 with one equivalent of AgOTf led to the formation of 5-SIDipp·HBCl(OTf) (4) and 5-SIDipp·PhBCl(OTf) (5a), where all the substituents on the boron atoms are different. The addition of two equivalents of AgNO3 to 2 leads to the formation of rare di-nitro substituted 5-SIDipp·BPh(NO3)2 (6). Further, the reaction of 5-SIDipp with B(C6F5)3 in tetrahydrofuran and diethyl ether shows a frustrated Lewis pair type small molecule activated products, 7 and 8.
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36
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Kawamoto T, Fukuyama T, Picard B, Ryu I. New directions in radical carbonylation chemistry: combination with electron catalysis, photocatalysis and ring-opening. Chem Commun (Camb) 2022; 58:7608-7617. [PMID: 35758516 DOI: 10.1039/d2cc02700c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Radical carbonylation offers potent methods for introducing carbon monoxide into organic molecules. This feature article focuses on our current efforts to develop new strategies for radical carbonylation, which include electron-transfer carbonylation, site-selective C(sp3)-H carbonylation by a photocatalyst and ring-opening carbonylation.
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Affiliation(s)
- Takuji Kawamoto
- Department of Applied Chemistry, Yamaguchi University, Ube, Yamaguchi, 755-8611, Japan
| | - Takahide Fukuyama
- Department of Chemistry, Osaka Metropolitan University (OMU), Sakai, Osaka, 599-8531, Japan
| | - Baptiste Picard
- Organization for Research Promotion, Osaka Metropolitan University (OMU), Sakai, Osaka, 599-8531, Japan.
| | - Ilhyong Ryu
- Organization for Research Promotion, Osaka Metropolitan University (OMU), Sakai, Osaka, 599-8531, Japan. .,Department of Applied Chemistry, National Yang Ming Chiao Tung University (NYCU), Hsinchu, 30010, Taiwan
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37
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Deka R, Orthaber A. Carbene chemistry of arsenic, antimony, and bismuth: origin, evolution and future prospects. Dalton Trans 2022; 51:8540-8556. [PMID: 35578901 DOI: 10.1039/d2dt00755j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The discovery of the first isolable N-heterocyclic carbene in 1991 ushered in a new era in coordination chemistry. The remarkable bonding properties of carbenes have led to their rapid proliferation as auxiliary ligands for a wide range of transition metals and main group elements. In the case of group 15, while carbene-stabilized nitrogen and phosphorus compounds are extensively studied, the scope of research has shrunk significantly from arsenic to bismuth. This is essentially attributed to the decrease in stability of the C-E bond upon descending the group. Even so, modulating the carbene backbone or introducing alternative synthetic strategies not only alleviates the stability issues but also offers promising results in terms of the bonding and reactivities of these compounds. The purpose of the present perspective is to provide a comprehensive overview of the origins and development of carbene chemistry of arsenic, antimony, and bismuth, as well as to highlight the future prospects of this field.
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Affiliation(s)
- Rajesh Deka
- Synthetic Molecular Chemistry, Department of Chemistry - Ångström laboratories, Uppsala University, Box 523, 75120 Uppsala, Sweden.
| | - Andreas Orthaber
- Synthetic Molecular Chemistry, Department of Chemistry - Ångström laboratories, Uppsala University, Box 523, 75120 Uppsala, Sweden.
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38
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Construction of boron-stereogenic compounds via enantioselective Cu-catalyzed desymmetric B-H bond insertion reaction. Nat Commun 2022; 13:2624. [PMID: 35552397 PMCID: PMC9098526 DOI: 10.1038/s41467-022-30287-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/21/2022] [Indexed: 01/15/2023] Open
Abstract
Compared with the well-developed carbon-stereogenic chemistry, the construction of boron-stereogenic compounds remains undeveloped and challenging. Herein, the previously elusive catalytic enantioselective construction of boron-stereogenic compounds has been achieved through enantioselective desymmetric B-H bond insertion reaction. The B-H bond insertion reaction of 2-arylpyridine-boranes with versatile diazo compounds under chiral copper catalyst can afford boron-stereogenic compounds with good to excellent enantioselectivity. Moreover, the synthetic utility of this reaction is demonstrated by the scalability and downstream transformations. DFT calculations provide insights into the reaction mechanism and the origin of stereoselectivity.
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39
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Major CJ, Qu ZW, Grimme S, Stephan DW. The Non-Ancillary Nature of Trimethylsilylamide Substituents in Boranes and Borinium Cations. Chemistry 2022; 28:e202200698. [PMID: 35262980 PMCID: PMC9324859 DOI: 10.1002/chem.202200698] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Indexed: 11/21/2022]
Abstract
The known boranes (R(Me3Si)N)2BF (R=Me3Si 1, tBu 2, C6F53, o‐tol 4, Mes 5, Dipp 6) and borinium salts (R(Me3Si)N)2B][B(C6F5)4] (R=Me3Si 7, tBu 8) are prepared and fully characterized. Compound 7 is shown to react with phosphines to generate [R3PSiMe3]+ and [R3PH]+ (R=Me, tBu). Efforts to generate related borinium cations via fluoride abstraction from (R(Me3Si)N)2BF (R=C6F53, o‐tol 4, Mes 5) gave complex mixtures suggesting multiple reaction pathways. However for R=Dipp 6, the species [(μ‐F)(SiMe2N(Dipp))2BMe][B(C6F5)4] was isolated as the major product, indicating methyl abstraction from silicon and F/Me exchange on boron. These observations together with state‐of‐the‐art DFT mechanistic studies reveal that the trimethylsilyl‐substituents do not behave as ancillary subsitutents but rather act as sources of proton, SiMe3 and methyl groups.
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Affiliation(s)
- Christopher J Major
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115, Bonn, Germany
| | - Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada
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40
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Ding Z, Liu Z, Wang Z, Yu T, Xu M, Wen J, Yang K, Zhang H, Xu L, Li P. Catalysis with Diboron(4)/Pyridine: Application to the Broad-Scope [3 + 2] Cycloaddition of Cyclopropanes and Alkenes. J Am Chem Soc 2022; 144:8870-8882. [PMID: 35532758 DOI: 10.1021/jacs.2c03673] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In contrast to the extensive but non-recyclable use of tetraalkoxydiboron(4) compounds as stoichiometric reagents in diverse reactions, this article reports an atom-economical reaction using a commercial diboron(4) as the catalyst. The key to success was designing a catalytic cycle for radical [3 + 2] cycloaddition involving a pyridine cocatalyst to generate from the diboron(4) catalyst and reversibly mediate the transfer of boronyl radicals. In comparison with known [3 + 2] cycloaddition with transition metal-based catalysts, the current reaction features not only metal-free conditions, inexpensive and stable catalysts, and simple operation but also remarkably broadened substrate scope. In particular, previously unusable cyclopropyl ketones without an activating group and/or alkenes with 1,2-disubstitution and 1,1,2-trisubstitution patterns were successfully used for the first time. Consequently, challenging cyclopentane compounds with various levels of substitution (65 examples, 57 new products, up to six substituents at all five ring atoms) were readily prepared in generally high to excellent yield and diastereoselectivity. The reaction was also successfully applied in concise formal synthesis of an anti-obesity drug and building natural product-like complex bridged or spirocyclic compounds. Mechanistic experiments and computational investigation support the proposed radical relay catalysis featuring a pyridine-assisted boronyl radical catalyst. Overall, this work demonstrates the first approach to use tetraalkoxydiboron(4) compounds as catalysts and may lead to the development of new, green, and efficient transition metal-like boron-catalyzed organic reactions.
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Affiliation(s)
- Zhengwei Ding
- Department of Medicinal Chemistry, School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Zhi Liu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Zhijun Wang
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Tao Yu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Ming Xu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Jingru Wen
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Kaiyan Yang
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Hailong Zhang
- Department of Medicinal Chemistry, School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Liang Xu
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Pengfei Li
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China.,State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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41
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Zhang Y, Liao Y, Liu P, Ran Y, Liu X. Radical borylation of vinyl azides with NHC-boranes: divergent synthesis of α-boryl ketones and borylated triazoles. Org Biomol Chem 2022; 20:3550-3557. [PMID: 35411904 DOI: 10.1039/d2ob00076h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A divergent radical borylation of vinyl azides with N-heterocyclic carbene (NHC) boranes in the presence of tBuSH is described. The protocol enables the divergent synthesis of α-boryl ketones and borylated triazoles with excellent functional group tolerance and a broad substrate scope. Remarkably, this work shows that vinyl azides can serve as unprecedented five-atom synthons for the construction of 1,2,3-triazoles without N2 extrusion.
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Affiliation(s)
- Yifei Zhang
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China.
| | - Yangzhen Liao
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China.
| | - Peijun Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China. .,Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi 563000, China
| | - Yu Ran
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China.
| | - Xiaozu Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China. .,Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi 563000, China
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42
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Li S, Xie Z. Visible-Light-Promoted Nickel-Catalyzed Cross-Coupling of Iodocarboranes with (Hetero)Arenes via Boron-Centered Carboranyl Radicals. J Am Chem Soc 2022; 144:7960-7965. [PMID: 35451827 DOI: 10.1021/jacs.2c02329] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A general strategy for the generation of hypervalent boron-centered carboranyl radicals at the B(3), B(4), and B(9) positions has been developed for the first time via visible-light-promoted iodine atom abstraction from iodo-o-carboranes by low-valent nickel complex. These radicals react with various (hetero)arenes to afford a wide range of cage B-arylated carborane derivatives at room temperature in very good to excellent yields with a broad substrate scope. Their electrophilicities are dependent on the vertex charges of the cage and follow the order B(3) > B(4) > B(9). Both visible light and nickel catalyst are proved critical to the generation of boron-centered carboranyl radicals. The involvement of boron radicals is supported by control experiments. A reaction mechanism associated with these reactions is also proposed. This strategy offers a new protocol for the generation of boron-centered carboranyl radicals at the selected boron vertex, leading to a facile synthesis of a large class of cage boron substituted carborane molecules.
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Affiliation(s)
- Shimeng Li
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong 999077, China
| | - Zuowei Xie
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong 999077, China
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43
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Taniguchi T. Substituent Effects of Tetracoordinate Boron in Organic Synthesis. Chemistry 2022; 28:e202104333. [DOI: 10.1002/chem.202104333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Indexed: 12/15/2022]
Affiliation(s)
- Tsuyoshi Taniguchi
- Graduate School of Natural Science and Technology Kanazawa University Kakuma-machi Kanazawa 920-1192 Japan
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44
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Kundu G, Ajithkumar VS, Raj KV, Vanka K, Tothadi S, Sen SS. Substitution at sp 3 boron of a six-membered NHC·BH 3: convenient access to a dihydroxyborenium cation. Chem Commun (Camb) 2022; 58:3783-3786. [PMID: 35229841 DOI: 10.1039/d1cc06816d] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we have undertaken the synthesis and investigated the reactivity of a 6-membered saturated NHC borane adduct (1). Direct electrophilic halogenation of 1 with a stoichiometric amount of I2 led to NHC boryl iodides, 6-SIDipp·BH2I (2) and 6-SIDipp·BHI2 (3), which were further reacted with various nucleophiles to give novel 6-SIDipp based mono and disubstituted boranes with OTf (4 and 6) or ONO2 (5 and 7) functional groups. The addition of Br2/H2O to 1 smoothly results in a dihydroxyborenium cation (8).
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Affiliation(s)
- Gargi Kundu
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - V S Ajithkumar
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - K Vipin Raj
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.,Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.,Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
| | - Srinu Tothadi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.,Analytical and Environmental Sciences Division and Centralized Instrumentation Facility, CSIR-Central Salt and Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavnagar-364002, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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45
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Chen ZL, Empel C, Wang K, Wu PP, Cai BG, Li L, Koenigs RM, Xuan J. Enabling Cyclopropanation Reactions of Imidazole Heterocycles via Chemoselective Photochemical Carbene Transfer Reactions of NHC-Boranes. Org Lett 2022; 24:2232-2237. [PMID: 35274531 DOI: 10.1021/acs.orglett.2c00609] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Herein we report a site-selective cyclopropanation of N-heterocyclic carbene (NHC)-borane complexes via photochemical carbene transfer reactions. By subtle changes to the reaction conditions, this approach can be further extended toward the difunctionalization of NHC-boranes via cyclopropanation and the B-H insertion reaction. Further investigations in photochemical continuous-flow applications and synthetic transformations proved the utility of the method. Theoretical calculations and control experiments were performed to explain the observed selectivity.
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Affiliation(s)
- Ze-Le Chen
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Claire Empel
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany
| | - Kun Wang
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Pan-Pan Wu
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Bao-Gui Cai
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Lei Li
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Rene M Koenigs
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany
| | - Jun Xuan
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China.,Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Hefei 230601, China
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46
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Abstract
Borenium ions are strong Lewis acids because of the positive charge on boron. While their high reactivity had long restricted their role in organic synthesis to stoichiometric reagents, in the past ten years the introduction of suitable supporting ligands, such as N-heterocyclic carbenes, has enabled them to function as competent catalysts for various organic transformations involving the activation of strong covalent bonds, such as H-H, Si-H, B-H, C-H and C-C bonds. This review provides an overview of the recent advances in borenium-catalysed reactions with emphasis on catalyst synthesis, methodology development and mechanistic insight.
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Affiliation(s)
- Xinyue Tan
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai, 200438, P. R. China.
| | - Huadong Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai, 200438, P. R. China.
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47
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Das S, Sinha S, Roymahapatra G, De GC, Giri S. Ligand effect on the stability, reactivity, and acidity of imidazolium systems. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Subhra Das
- School of Applied Science and Humanities Haldia Institute of Technology, ICARE Complex Haldia West Bengal India
- Department of Chemistry Cooch Behar Panchanan Barma University Cooch Behar West Bengal India
| | - Swapan Sinha
- School of Applied Science and Humanities Haldia Institute of Technology, ICARE Complex Haldia West Bengal India
| | - Gourisankar Roymahapatra
- School of Applied Science and Humanities Haldia Institute of Technology, ICARE Complex Haldia West Bengal India
| | - Gobinda Chandra De
- Department of Chemistry Cooch Behar Panchanan Barma University Cooch Behar West Bengal India
| | - Santanab Giri
- School of Applied Science and Humanities Haldia Institute of Technology, ICARE Complex Haldia West Bengal India
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48
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Miao YQ, Pan QJ, Liu Z, Chen X. Visible-light-induced 1,2-diphenyldisulfane-catalyzed regioselective hydroboration of electron-deficient alkenes. NEW J CHEM 2022. [DOI: 10.1039/d2nj03930c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A photoinduced PhSSPh-catalyzed regioselective borylation of electron-deficient alkenes has been developed for the synthesis of borylated carbonyl, nitrile, sulfone, phosphonate, trifluoromethyl, and gem-diboron compounds.
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Affiliation(s)
- Yu-Qi Miao
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, China
| | - Qiao-Jing Pan
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, China
| | - Zhenxing Liu
- College of Chemistry, Zhengzhou University, Zhengzhou, Henan, China
| | - Xuenian Chen
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, China
- College of Chemistry, Zhengzhou University, Zhengzhou, Henan, China
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49
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Kundu G, Dixit R, Tothadi S, Vanka K, Sen SS. Versatile chemistry of six-membered NHC with boranes: bromination at sp3 borane, activation of B–H bond of HBpin, and ring expansion of NHC. Dalton Trans 2022; 51:14452-14457. [DOI: 10.1039/d2dt01707e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The NHC•borane chemistry has been majorly restricted to imidazol-2-ylidene classes of carbenes. In our previous communication, we have reported the synthesis of 6-SIDipp•BH3 [6-SIDipp = 1,3-di(2,6-diisopropylphenyl) tetrahydropyrimidine-2-ylidene] and its electrophilic...
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50
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Merschel A, Vishnevskiy YV, Neumann B, Stammler G, Ghadwal RS. Crystalline phosphino-functionalized mesoionic olefins (p-MIOs). Dalton Trans 2022; 51:8217-8222. [DOI: 10.1039/d2dt01314b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphino-functionalized mesoionic olefins (p-MIOs), (iMIC)CHR (iMIC = PhC{N(Dipp)}2C(PPh2)C, Dipp = 2,6-iPr2C6H3; R = H 4a or Ph 4b) derived from a 1,3-imidazole based mesoionic carbene (iMIC) are reported. The p-MIOs...
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