1
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Willcox DR, Cocco E, Nichol GS, Carlone A, Thomas SP. Catalytic Access to Diastereometrically Pure Four- and Five-Membered Silyl-Heterocycles Using Transborylation. Angew Chem Int Ed Engl 2024; 63:e202401737. [PMID: 38578174 DOI: 10.1002/anie.202401737] [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: 01/24/2024] [Revised: 03/19/2024] [Accepted: 04/03/2024] [Indexed: 04/06/2024]
Abstract
Silyl-heterocycles offer a unique handle to expand and explore chemical space, reactivity, and functionality. The shortage of catalytic methods for the preparation of diverse and functionalized silyl-heterocycles however limits widespread exploration and exploitation. Herein the borane-catalyzed intramolecular 1,1-carboboration of silyl-alkynes has been developed for the synthesis of 2,3-dihydrosilolyl and silylcyclobut-2-enyl boronic esters. Successful, catalytic carboboration has been achieved on a variety of functionally diverse silyl-alkynes, using a borane catalyst and transborylation-enabled turnover. Mechanistic studies, including 13C-labelling, computational studies, and single-turnover experiments, suggest a reaction pathway proceeding by 1,2-hydroboration, 1,1-carboboration, and transborylation to release the alkenyl boronic ester product and regenerate the borane catalyst.
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Affiliation(s)
- Dominic R Willcox
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ, Edinburgh, United Kingdom
| | - Emanuele Cocco
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ, Edinburgh, United Kingdom
- Department of Physical and Chemical Sciences, Università degli Studi dell'Aquila, via Vetoio, 67100, L'Aquila, Italy
| | - Gary S Nichol
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ, Edinburgh, United Kingdom
| | - Armando Carlone
- Department of Physical and Chemical Sciences, Università degli Studi dell'Aquila, via Vetoio, 67100, L'Aquila, Italy
| | - Stephen P Thomas
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ, Edinburgh, United Kingdom
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2
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Mao X, Lu Z, Zhang J, Xie Z. Catalyst-Free Regioselective Diborylation of Aryllithium with Tetra(o-tolyl)diborane(4). Angew Chem Int Ed Engl 2024; 63:e202317614. [PMID: 38123525 DOI: 10.1002/anie.202317614] [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: 11/19/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 12/23/2023]
Abstract
A catalyst-free 1,2-diborylation of aryllithium with tetra(o-tolyl)diborane(4) has been achieved, giving a series of 1,2-diborylaryl lithium species in excellent yields under mild reaction conditions, which leads to 1,2-di(tolyl)borylarenes in 60-91 % yields upon treatment with the hydride-abstracting reagent. In these transformations, one sp2 C-H of arene is activated and both boryl units are utilized to build two new (sp2 )C-B bonds. This represents a new strategy for selective arene diborylation. Density functional theory (DFT) calculations suggest that an aromatic nucleophilic substitution is a key step in the formation of the products.
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Affiliation(s)
- Xiaofeng Mao
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China
| | - Zhenpin Lu
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Jie Zhang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China
| | - Zuowei Xie
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
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3
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Zhang X, Liu C, Wei W, Zhang Z, Liang T. Iodine-dependent oxidative regioselective aminochalcogenation of indolines. Chem Commun (Camb) 2024; 60:1152-1155. [PMID: 38189976 DOI: 10.1039/d3cc05999e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
A directing-group-free strategy for oxidative regioselective aminochalcogenation of indolines with amines and dichalconides is presented. This strategy combines tandem coupling sequences and oxidative dehydrogenation methods in a multi-component reaction, enabling the fast construction of a series of C2,3- or C2,5-aminochalcogenated indole derivatives. Moreover, the application of this synthetic approach is demonstrated through the late-stage modification of pharmaceuticals and the derivatization of the products, highlighting its potential and significance.
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Affiliation(s)
- Xiaoxiang Zhang
- Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, People's Republic of China.
| | - Chenrui Liu
- Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, People's Republic of China.
| | - Wanxing Wei
- Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, People's Republic of China.
| | - Zhuan Zhang
- Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, People's Republic of China.
| | - Taoyuan Liang
- Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, People's Republic of China.
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4
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Zhang J, Chen Z, Chen M, Zhou Q, Zhou R, Wang W, Shao Y, Zhang F. Lanthanide/B(C 6F 5) 3-Promoted Hydroboration Reduction of Indoles and Quinolines with Pinacolborane. J Org Chem 2024. [PMID: 38178689 DOI: 10.1021/acs.joc.3c01767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
We have developed a lanthanide/B(C6F5)3-promoted hydroboration reduction of indoles and quinolines with pinacolborane (HBpin). This reaction provides streamlined access to a range of nitrogen-containing compounds in moderate to excellent yields. Large-scale synthesis and further transformations to bioactive compounds indicate that the method has potential practical applications. Preliminary mechanistic studies suggest that amine additives promote the formation of indole-borane intermediates, and the lanthanide/B(C6F5)3-promoted hydroboration reduction proceeds via hydroboration of indole-borane intermediates with HBpin and in situ-formed BH3 species, followed by the protodeborylation process.
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Affiliation(s)
- Jianping Zhang
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Ziyan Chen
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Mingxin Chen
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Qi Zhou
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Rongrong Zhou
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Wenli Wang
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Yinlin Shao
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
- Institute of New Materials & Industrial Technology, Wenzhou University, Wenzhou 325035, China
| | - Fangjun Zhang
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
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5
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Tendera L, Kuehn L, Marder TB, Radius U. On the Reactivity of a NHC Nickel Bis-Boryl Complex: Reductive Elimination and Formation of Mono-Boryl Complexes. Chemistry 2023; 29:e202302310. [PMID: 37551752 DOI: 10.1002/chem.202302310] [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: 07/19/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/09/2023]
Abstract
The synthesis of the first terminal mono-boryl complexes of nickel, which are not stabilized by a pincer ligand, is reported. The reaction of the nickel bis-boryl complex cis-[Ni(i Pr2 ImMe )2 (Bcat)2 ] 1 (cat=1,2-O2 C6 H4 ) with the small donor ligand PMe3 led to a complete ligand exchange at nickel with reductive elimination of B2 cat2 and formation of the bis-NHC adduct [B2 cat2 ⋅ (i Pr2 ImMe )2 ] 3 and [Ni(PMe3 )4 ] 2 as the metal-containing species. Electrophilic attack of MeI on complex 1 or ligand dismutation of 1 with trans-[Ni(i Pr2 ImMe )2 Br2 ] led to loss of only one boryl ligand of 1 and afforded the nickel mono-boryl complexes trans-[Ni(i Pr2 ImMe )2 (Bcat)Br] 4 a and trans-[Ni(i Pr2 ImMe )2 (Bcat)I] 4 b.
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Affiliation(s)
- Lukas Tendera
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Laura Kuehn
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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6
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Wang T, Wang ZJ, Wang M, Wu L, Fang X, Liang Y, Lv J, Shi Z. Metal-Free Stereoconvergent C-H Borylation of Enamides. Angew Chem Int Ed Engl 2023; 62:e202313205. [PMID: 37721200 DOI: 10.1002/anie.202313205] [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: 09/06/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/19/2023]
Abstract
Enamides, functional derivatives of enamines, play a significant role as synthetic targets. However, the stereoselective synthesis of these molecules has posed a longstanding challenge in organic chemistry, particularly for acyclic enamides that are less thermodynamically stable. In this study, we present a general strategy for constructing β-borylenamides by C-H borylation, which provides a versatile platform for generating the stereodefined enamides. Our approach involves the utilization of metalloid borenium cation, generated through the reaction of BBr3 and enamides in the presence of two different additives, avoiding any exogenous catalyst. Importantly, the stereoconvergent nature of this methodology allows for the use of starting materials with mixed E/Z configurations, thus highlighting the unique advantage of this chemistry. Mechanistic investigations have shed light on the pivotal roles played by the two additives, the reactive boron species, and the phenomenon of stereoconvergence.
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Affiliation(s)
- Tianhang Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Zheng-Jun Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
- 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, Zhejiang, 325035, China
| | - Minyan Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Lei Wu
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Xiaowu Fang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Yong Liang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Jiahang Lv
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Zhuangzhi Shi
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, China
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, China
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7
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Al Mamari HH, Borel J, Hickey A, Courtney E, Merz J, Zhang X, Friedrich A, Marder TB, McGlacken GP. Regioselective Iridium-Catalyzed C8-H Borylation of 4-Quinolones via Transient O-Borylated Quinolines. Chemistry 2023; 29:e202301734. [PMID: 37280155 DOI: 10.1002/chem.202301734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/04/2023] [Accepted: 06/05/2023] [Indexed: 06/08/2023]
Abstract
The quinolone-quinoline tautomerization is harnessed to effect the regioselective C8-borylation of biologically important 4-quinolones by using [Ir(OMe)(cod)]2 as the catalyst precursor, the silica-supported monodentate phosphine Si-SMAP as the ligand, and B2 pin2 as the boron source. Initially, O-borylation of the quinoline tautomer takes place. Critically, the newly formed 4-(pinBO)-quinolines then undergo N-directed selective Ir-catalyzed borylation at C8. Hydrolysis of the OBpin moiety on workup returns the system to the quinolone tautomer. The C8-borylated quinolines were converted to their corresponding potassium trifluoroborate (BF3 K) salts and to their C8-chlorinated quinolone derivatives. The two-step C-H borylation-chlorination reaction sequence resulted in various C8-Cl quinolones in good yields. Conversion to C8-OH-, C8-NH2 -, and C8-Ar-substituted quinolones was also feasible by using this methodology.
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Affiliation(s)
- Hamad H Al Mamari
- Department of Chemistry, College of Science, Sultan Qaboos University, PO Box 36, Al Khoudh 123, Muscat, Sultanate of Oman
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Julie Borel
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Aobha Hickey
- School of Chemistry & Analytical and, Biological Chemistry Research Facility, University College Cork, T12 YN60, Ireland
| | - Eimear Courtney
- School of Chemistry & Analytical and, Biological Chemistry Research Facility, University College Cork, T12 YN60, Ireland
| | - Julia Merz
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Xiaolei Zhang
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Alexandra Friedrich
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Gerard P McGlacken
- School of Chemistry & Analytical and, Biological Chemistry Research Facility, University College Cork, T12 YN60, Ireland
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8
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Tendera L, Fantuzzi F, Marder TB, Radius U. Nickel boryl complexes and nickel-catalyzed alkyne borylation. Chem Sci 2023; 14:2215-2228. [PMID: 36845942 PMCID: PMC9945561 DOI: 10.1039/d2sc04690c] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/27/2023] [Indexed: 01/28/2023] Open
Abstract
The first nickel bis-boryl complexes cis-[Ni( i Pr2ImMe)2(Bcat)2], cis-[Ni( i Pr2ImMe)2(Bpin)2] and cis-[Ni( i Pr2ImMe)2(Beg)2] are reported, which were prepared via the reaction of a source of [Ni( i Pr2ImMe)2] with the diboron(4) compounds B2cat2, B2pin2 and B2eg2 ( i Pr2ImMe = 1,3-di-iso-propyl-4,5-dimethylimidazolin-2-ylidene; B2cat2 = bis(catecholato)diboron; B2pin2 = bis(pinacolato)diboron; B2eg2 = bis(ethylene glycolato)diboron). X-ray diffraction and DFT calculations strongly suggest that a delocalized, multicenter bonding scheme dictates the bonding situation of the NiB2 moiety in these square planar complexes, reminiscent of the bonding situation of "non-classical" H2 complexes. [Ni( i Pr2ImMe)2] also efficiently catalyzes the diboration of alkynes using B2cat2 as the boron source under mild conditions. In contrast to the known platinum-catalyzed diboration, the nickel system follows a different mechanistic pathway, which not only provides the 1,2-borylation product in excellent yields, but also provides an efficient approach to other products such as C-C coupled borylation products or rare tetra-borylated compounds. The mechanism of the nickel-catalyzed alkyne borylation was examined by means of stoichiometric reactions and DFT calculations. Oxidative addition of the diboron reagent to nickel is not dominant; the first steps of the catalytic cycle are coordination of the alkyne to [Ni( i Pr2ImMe)2] and subsequent borylation at the coordinated and, thus, activated alkyne to yield complexes of the type [Ni(NHC)2(η2-cis-(Bcat)(R)C[double bond, length as m-dash]C(R)(Bcat))], exemplified by the isolation and structural characterization of [Ni( i Pr2ImMe)2(η2-cis-(Bcat)(Me)C[double bond, length as m-dash]C(Me)(Bcat))] and [Ni( i Pr2ImMe)2(η2-cis-(Bcat)(H7C3)C[double bond, length as m-dash]C(C3H7)(Bcat))].
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Affiliation(s)
- Lukas Tendera
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of KentPark Wood RdCanterburyCT2 7NHUK
| | - Todd B. Marder
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität WürzburgAm Hubland97074 WürzburgGermany,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität WürzburgAm Hubland97074 WürzburgGermany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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9
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Saikia R, Das S, Almin A, Mahanta A, Sarma B, Thakur AJ, Bora U. N, N′-Dimethylurea as an efficient ligand for the synthesis of pharma-relevant motifs through Chan–Lam cross-coupling strategy. Org Biomol Chem 2023; 21:3143-3155. [PMID: 36987866 DOI: 10.1039/d3ob00176h] [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
The combination of copper and N,N′-dimethylurea is used to showcase the Chan–Lam N-arylation of three different nitrogen nucleophiles. The synthesized catalyst is cheap, chemoselective, and also found to be effective in the N-arylation of target APIs.
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Affiliation(s)
- Rakhee Saikia
- Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam 784028, India.
| | - Sanghamitra Das
- Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam 784028, India.
| | - Arzu Almin
- Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam 784028, India.
| | - Abhijit Mahanta
- Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam 784028, India.
- Department of Chemistry, Digboi College, Tinsukia, Assam-786171, India
| | - Bipul Sarma
- Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam 784028, India.
| | - Ashim J Thakur
- Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam 784028, India.
| | - Utpal Bora
- Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam 784028, India.
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10
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Wang F, Chen C, Zhang F, Meng Q. Comprehensive Theoretical Study of Nickel‐NHC‐catalyzed Enantioselective Intramolecular Indole C‐H Cyclization: Reaction Mechanism, Reactivity, Regioselectivity, and Electronic Processes. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6851] [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)
- Fen Wang
- College of Chemistry and Chemical Engineering, Taishan University Taian Shandong China
| | - Changbao Chen
- College of Chemistry and Material Science, Shandong Agricultural University Taian Shandong People’s Republic of China
- Key Laboratory of Agricultural Film Application, Ministry of Agriculture and Rural Affairs China
| | - Feng Zhang
- Technology Center, China Tobacco Fujian Industrial Co., Ltd. Xiamen Fujian China
| | - Qingxi Meng
- College of Chemistry and Material Science, Shandong Agricultural University Taian Shandong People’s Republic of China
- Key Laboratory of Agricultural Film Application, Ministry of Agriculture and Rural Affairs China
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11
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Pahl J, Noone E, Uzelac M, Yuan K, Ingleson MJ. Borylation Directed Borylation of Indoles Using Pyrazabole Electrophiles: A One-Pot Route to C7-Borylated-Indolines. Angew Chem Int Ed Engl 2022; 61:e202206230. [PMID: 35686751 PMCID: PMC9401042 DOI: 10.1002/anie.202206230] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Indexed: 12/23/2022]
Abstract
Pyrazabole (1) is a readily accessible diboron compound that can be transformed into ditopic electrophiles. In 1 (and derivatives), the B⋅⋅⋅B separation is ca. 3 Å, appropriate for one boron centre bonding to N and one to the C7 of indoles and indolines. This suitable B⋅⋅⋅B separation enables double E-H (E=N/C) functionalisation of indoles and indolines. Specifically, the activation of 1 with HNTf2 generates an electrophile that transforms N-H indoles and indolines into N/C7-diborylated indolines, with N-H borylation directing subsequent C7-H borylation. Indole reduction to indoline occurs before C-H borylation and our studies indicate this proceeds via hydroboration-C3-protodeboronation to produce an intermediate that then undergoes C7 borylation. The borylated products can be converted in situ into C7-BPin-N-H-indolines. Overall, this represents a transient directed C-H borylation to form useful C7-BPin-indolines.
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Affiliation(s)
- Jürgen Pahl
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Emily Noone
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Marina Uzelac
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Kang Yuan
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
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12
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Tendera L, Krummenacher I, Radius U. Cationic Nickel d9‐Metalloradicals [Ni(NHC)2]+. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Lukas Tendera
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Anorganische Chemie GERMANY
| | - Ivo Krummenacher
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Anorganische Chemie GERMANY
| | - Udo Radius
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Institut für Anorganische Chemie Am Hubland 97074 Würzburg GERMANY
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13
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Hazra S, Mahato S, Kanti Das K, Panda S. Transition-Metal-Free Heterocyclic Carbon-Boron Bond Formation. Chemistry 2022; 28:e202200556. [PMID: 35438817 DOI: 10.1002/chem.202200556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Indexed: 12/16/2022]
Abstract
Heteroaryl boronic acids and esters are extremely important and valuable intermediates because of their wide application in the synthesis of marketed drugs and bioactive compounds. Over the last couple of decades, the construction of highly important heteroaryl carbon-boron bonds has created huge attention. The transition-metal-free protocols are more green, less sensitive to air and moisture, and also economically advantageous over the transition-metal-based protocols. The transition-metal-free C-H borylation of heteroarenes and C-X (X=halogen) borylation of heteroaryl halides represents an excellent approach for their synthesis. Also, various cyclization and alkyne activation protocols have been recently established for their synthesis. The goal of this review article is to summarize the existing literature and the current state of the art for transition-metal-free synthesis of heteroaryl boronic acid and esters.
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Affiliation(s)
- Subrata Hazra
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - Somenath Mahato
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - Kanak Kanti Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - Santanu Panda
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
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14
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Hickey A, Merz J, Al Mamari HH, Friedrich A, Marder TB, McGlacken GP. Iridium-Catalyzed Borylation of 6-Fluoroquinolines: Access to 6-Fluoroquinolones. J Org Chem 2022; 87:9977-9987. [PMID: 35839386 PMCID: PMC9368603 DOI: 10.1021/acs.joc.2c00973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The Ir-catalyzed C–H borylation of fluoroquinolines
has
been realized. The quinoline boronic ester formed undergoes a range
of
important transformations of relevance to medicinal chemistry. Judicious
choice of the substituent at C4 on the quinoline facilitated the unmasking
of a fluoroquinolone—the core structure of many antibiotics.
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Affiliation(s)
- Aobha Hickey
- School of Chemistry & Analytical and Biological Chemistry Research Facility, University College Cork, Cork T12 YN60, Ireland
| | - Julia Merz
- Institute for Inorganic Chemistry, and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Hamad H Al Mamari
- Institute for Inorganic Chemistry, and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Department of Chemistry, College of Science, Sultan Qaboos University, P.O. Box 36, Al Khoudh 123 Muscat, Sultanate of Oman
| | - Alexandra Friedrich
- Institute for Inorganic Chemistry, and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Todd B Marder
- Institute for Inorganic Chemistry, and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Gerard P McGlacken
- School of Chemistry & Analytical and Biological Chemistry Research Facility, University College Cork, Cork T12 YN60, Ireland.,Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork T12 YN60, Ireland
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15
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Pahl J, Noone E, Uzelac M, Yuan K, Ingleson M. Borylation Directed Borylation of Indoles Using Pyrazabole Electrophiles: A One‐Pot Route to C7‐Borylated‐Indolines. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- J. Pahl
- University of Edinburgh Chemistry UNITED KINGDOM
| | - E. Noone
- University of Edinburgh Chemistry UNITED KINGDOM
| | - M. Uzelac
- University of Edinburgh Chemistry UNITED KINGDOM
| | - K. Yuan
- University of Edinburgh Chemistry UNITED KINGDOM
| | - Michael Ingleson
- University of Edinburgh Chemistry South Bridge EH8 9YL Edinburgh UNITED KINGDOM
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16
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Bisht R, Haldar C, Hassan MMM, Hoque ME, Chaturvedi J, Chattopadhyay B. Metal-catalysed C-H bond activation and borylation. Chem Soc Rev 2022; 51:5042-5100. [PMID: 35635434 DOI: 10.1039/d1cs01012c] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Transition metal-catalysed direct borylation of hydrocarbons via C-H bond activation has received a remarkable level of attention as a popular reaction in the synthesis of organoboron compounds owing to their synthetic versatility. While controlling the site-selectivity was one of the most challenging issues in these C-H borylation reactions, enormous efforts of several research groups proved instrumental in dealing with selectivity issues that presently reached an impressive level for both proximal and distal C-H bond borylation reactions. For example, in the case of ortho C-H bond borylation reactions, innovative methodologies have been developed either by the modification of the directing groups attached with the substrates or by creating new catalytic systems via the design of new ligand frameworks. Whereas meta and para selective C-H borylations remained a formidable challenge, numerous innovative concepts have been developed within a very short period of time by the development of new catalytic systems with the employment of various noncovalent interactions. Moreover, significant advancements have occurred for aliphatic C(sp3)-H borylations as well as enantioselective borylations. In this review article, we aim to discuss and summarize the different approaches and findings related to the development of directed proximal ortho, distal meta/para, aliphatic (racemic and enantioselective) borylation reactions since 2014. Additionally, considering the C-H borylation reaction as one of the most important mainstream reactions, various applications of this C-H borylation reaction toward the synthesis of natural products, therapeutics, and applications in materials chemistry will be summarized in the last part of this review article.
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Affiliation(s)
- Ranjana Bisht
- Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, SGPGIMS Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India.
| | - Chabush Haldar
- Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, SGPGIMS Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India.
| | - Mirja Md Mahamudul Hassan
- Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, SGPGIMS Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India.
| | - Md Emdadul Hoque
- Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, SGPGIMS Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India.
| | - Jagriti Chaturvedi
- Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, SGPGIMS Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India.
| | - Buddhadeb Chattopadhyay
- Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, SGPGIMS Campus, Raebareli Road, Lucknow 226014, Uttar Pradesh, India.
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17
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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: 15] [Impact Index Per Article: 7.5] [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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18
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Kuehn L, Zapf L, Werner L, Stang M, Würtemberger-Pietsch S, Krummenacher I, Braunschweig H, Lacôte E, Marder TB, Radius U. NHC induced radical formation via homolytic cleavage of B–B bonds and its role in organic reactions. Chem Sci 2022; 13:8321-8333. [PMID: 35919710 PMCID: PMC9297536 DOI: 10.1039/d2sc02096c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/07/2022] [Indexed: 11/21/2022] Open
Abstract
New borylation methodologies have been reported recently, wherein diboron(4) compounds apparently participate in free radical couplings via the homolytic cleavage of the B–B bond. We report herein that bis-NHC adducts of the type (NHC)2·B2(OR)4, which are thermally unstable and undergo intramolecular ring expansion reactions (RER), are sources of boryl radicals of the type NHC–BR2˙, exemplified by Me2ImMe·Bneop˙ 1a (Me2ImMe = 1,3,4,5-tetramethyl-imidazolin-2-ylidene, neop = neopentylglycolato), which are formed by homolytic B–B bond cleavage. Attempts to apply the boryl moiety 1a in a metal-free borylation reaction by suppressing the RER failed. However, based on these findings, a protocol was developed using Me2ImMe·B2pin23 for the transition metal- and additive-free boryl transfer to substituted aryl iodides and bromides giving aryl boronate esters in good yields. Analysis of the side products and further studies concerning the reaction mechanism revealed that radicals are likely involved. An aryl radical was trapped by TEMPO, an EPR resonance, which was suggestive of a boron-based radical, was detected in situ, and running the reaction in styrene led to the formation of polystyrene. The isolation of a boronium cation side product, [(Me2ImMe)2·Bpin]+I−7, demonstrated the fate of the second boryl moiety of B2pin2. Interestingly, Me2ImMe NHC reacts with aryl iodides and bromides generating radicals. A mechanism for the boryl radical transfer from Me2ImMe·B2pin23 to aryl iodides and bromides is proposed based on these experimental observations. Bis-NHC adducts of the type (NHC)2·B2(OR)4 are sources of boryl radicals of the type NHC–BR2˙, which are formed by homolytic B–B bond cleavage.![]()
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Affiliation(s)
- Laura Kuehn
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ludwig Zapf
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Luis Werner
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martin Stang
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Sabrina Würtemberger-Pietsch
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Emmanuel Lacôte
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, CNES, ArianeGroup, LHCEP, Bât. Raulin, 2 rue Victor Grignard, F-69622 Villeurbanne, France
| | - Todd B. Marder
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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19
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Lv J, Zhang XJ, Wang M, Zhao Y, Shi Z. BBr 3 -Mediated P(III)-Directed C-H Borylation of Phosphines. Chemistry 2021; 28:e202104100. [PMID: 34878200 DOI: 10.1002/chem.202104100] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 01/09/2023]
Abstract
Transition-metal-catalyzed C-H borylation has been widely used in the preparation of organoboron compounds. Here, we developed a general protocol on metal-free P(III)-directed C-H borylation of phosphines mediated by BBr3 , resulting in the formation of products bearing both phosphorus and boron. The development of the metal-free strategy to mimic previous metallic processes has shown low cost, superior practicality, and environmental friendliness. Density functional theory (DFT) calculations demonstrate the preferred pathway for this metal-free directed C-H borylation process.
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Affiliation(s)
- Jiahang Lv
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China
| | - Xue-Jun Zhang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China.,Department of Orthopedic Surgery, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210093, P. R. China
| | - Minyan Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China
| | - Zhuangzhi Shi
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China.,School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, P. R. China
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20
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Zhang S, Xu H, He J, Zhang Y. Application of Mutualism in Organic Synthetic Chemistry: Mutually Promoted C−H Functionalization of Indole and Reduction of Quinoline. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Sutao Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry Jilin University Changchun Jilin 130012 People's Republic of China
| | - Hai Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry Jilin University Changchun Jilin 130012 People's Republic of China
| | - Jianghua He
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry Jilin University Changchun Jilin 130012 People's Republic of China
| | - Yuetao Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry Jilin University Changchun Jilin 130012 People's Republic of China
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21
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22
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Bose SK, Mao L, Kuehn L, Radius U, Nekvinda J, Santos WL, Westcott SA, Steel PG, Marder TB. First-Row d-Block Element-Catalyzed Carbon-Boron Bond Formation and Related Processes. Chem Rev 2021; 121:13238-13341. [PMID: 34618418 DOI: 10.1021/acs.chemrev.1c00255] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Organoboron reagents represent a unique class of compounds because of their utility in modern synthetic organic chemistry, often affording unprecedented reactivity. The transformation of the carbon-boron bond into a carbon-X (X = C, N, and O) bond in a stereocontrolled fashion has become invaluable in medicinal chemistry, agrochemistry, and natural products chemistry as well as materials science. Over the past decade, first-row d-block transition metals have become increasingly widely used as catalysts for the formation of a carbon-boron bond, a transformation traditionally catalyzed by expensive precious metals. This recent focus on alternative transition metals has enabled growth in fundamental methods in organoboron chemistry. This review surveys the current state-of-the-art in the use of first-row d-block element-based catalysts for the formation of carbon-boron bonds.
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Affiliation(s)
- Shubhankar Kumar Bose
- Centre for Nano and Material Sciences (CNMS), Jain University, Jain Global Campus, Bangalore-562112, India
| | - Lujia Mao
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, School of Pharmacy, Hainan Medical University, 571199 Haikou, Hainan, P. R. China
| | - Laura Kuehn
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jan Nekvinda
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Webster L Santos
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stephen A Westcott
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Patrick G Steel
- Department of Chemistry, University of Durham, Science Laboratories South Road, Durham DH1 3LE, U.K
| | - Todd B Marder
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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23
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Huang M, Hu J, Krummenacher I, Friedrich A, Braunschweig H, Westcott SA, Radius U, Marder TB. Base-Mediated Radical Borylation of Alkyl Sulfones. Chemistry 2021; 28:e202103866. [PMID: 34713940 PMCID: PMC9299846 DOI: 10.1002/chem.202103866] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Indexed: 11/06/2022]
Abstract
A practical and direct method was developed for the production of versatile alkylboronic esters via transition metal-free borylation of primary and secondary alkyl sulfones. The key to the success of the strategy is the use of bis(neopentyl glycolato) diboron (B 2 neop 2 ), with a stoichiometric amount of base as a promoter. The practicality and industrial potential of this protocol are highlighted by its wide functional group tolerance, the late-stage modification of complex compounds, no need for further transesterification, and operational simplicity. Radical clock, radical trap experiments, and EPR studies were conducted which show that the borylation process involves radical intermediates.
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Affiliation(s)
- Mingming Huang
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Institute for Inorganic Chemistry, GERMANY
| | - Jiefeng Hu
- Julius-Maximilians-Universität Würzburg, Institute for Inorganic Chemistry, GERMANY
| | - Ivo Krummenacher
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Institute For Inorganic Chemistry, GERMANY
| | - Alexandra Friedrich
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Institute for Inorganic Chemistry, GERMANY
| | - Holger Braunschweig
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Institute for Inorganic Chemistry, GERMANY
| | - Stephen A Westcott
- Mount Allison University, Department of Chemistry and Biochemistry, GERMANY
| | - Udo Radius
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Institute for Inorganic Chemistry, GERMANY
| | - Todd B Marder
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074, Würzburg, GERMANY
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24
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Zhang B, Zou Y, Wang L, Zhang H. Zinc catalysed C3-H borylation of indoles and 1,1-diboration of terminal alkynes. Chem Commun (Camb) 2021; 57:11185-11188. [PMID: 34622253 DOI: 10.1039/d1cc04497d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A low catalyst loading Zn(OTf)2-catalysed C3-H borylation of indoles with pinacolborane was developed. This transformation represents the use of an abundant, cheap and environmentally benign zinc catalyst in catalytic direct aromatic C-H borylation and offers a simple and prompt route towards the synthesis of C3-borylated indoles. The 1,1-diboration of terminal alkynes was also achieved using the same catalytic system to produce 1,1-diborylated alkenes.
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Affiliation(s)
- Binfeng Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Youliang Zou
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Li Wang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Hua Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
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25
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Wu M, Wang S, Wang Y, Gao H, Yi W, Zhou Z. TFA‐Prompted/Rh(III)‐Catalysed Chemoselective C
3
− or C
2
−H Functionalization of Indoles with Methylenecyclopropanes. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Min Wu
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Shengdong Wang
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Yi Wang
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Hui Gao
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Wei Yi
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Zhi Zhou
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
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26
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Sabater S, Schmidt D, Schmidt H(S, Kuntze‐Fechner MW, Zell T, Isaac CJ, Rajabi NA, Grieve H, Blackaby WJM, Lowe JP, Macgregor SA, Mahon MF, Radius U, Whittlesey MK. [Ni(NHC) 2 ] as a Scaffold for Structurally Characterized trans [H-Ni-PR 2 ] and trans [R 2 P-Ni-PR 2 ] Complexes. Chemistry 2021; 27:13221-13234. [PMID: 34190374 PMCID: PMC8518396 DOI: 10.1002/chem.202101484] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Indexed: 11/06/2022]
Abstract
The addition of PPh2 H, PPhMeH, PPhH2 , P(para-Tol)H2 , PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2 ] (NHC=IiPr2 , IMe4 , IEt2 Me2 ) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H-Ni-PR2 ] or novel trans [R2 P-Ni-PR2 ] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4 >IEt2 Me2 >IiPr2 ) and phosphines are employed. P-P activation of the diphosphines R2 P-PR2 (R2 =Ph2 , PhMe) provides an alternative route to some of the [Ni(NHC)2 (PR2 )2 ] complexes. DFT calculations capture these trends with P-H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni-P bond. P-P bond activation from [Ni(NHC)2 (Ph2 P-PPh2 )] adducts proceeds with computed barriers below 10 kcal mol-1 . The ability of the [Ni(NHC)2 ] moiety to afford isolable terminal phosphido products reflects the stability of the Ni-NHC bond that prevents ligand dissociation and onward reaction.
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Affiliation(s)
- Sara Sabater
- Department of ChemistryUniversity of Bath Claverton DownBathBA2 7AYUK
| | - David Schmidt
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | | | | | - Thomas Zell
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Connie J. Isaac
- Department of ChemistryUniversity of Bath Claverton DownBathBA2 7AYUK
| | - Nasir A. Rajabi
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
| | - Harry Grieve
- Department of ChemistryUniversity of Bath Claverton DownBathBA2 7AYUK
| | | | - John P. Lowe
- Department of ChemistryUniversity of Bath Claverton DownBathBA2 7AYUK
| | | | - Mary F. Mahon
- Department of ChemistryUniversity of Bath Claverton DownBathBA2 7AYUK
| | - Udo Radius
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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27
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Buono F, Nguyen T, Qu B, Wu H, Haddad N. Recent Advances in Nonprecious Metal Catalysis. Org Process Res Dev 2021. [DOI: 10.1021/acs.oprd.1c00053] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Frederic Buono
- Chemical Development US, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, Connecticut 06877, United States
| | - Thach Nguyen
- Chemical Development US, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, Connecticut 06877, United States
| | - Bo Qu
- Chemical Development US, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, Connecticut 06877, United States
| | - Hao Wu
- Chemical Development US, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, Connecticut 06877, United States
| | - Nizar Haddad
- Chemical Development US, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, Connecticut 06877, United States
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28
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Donnelly LJ, Faber T, Morrison CA, Nichol GS, Thomas SP, Love JB. C–H Borylation Catalysis of Heteroaromatics by a Rhenium Boryl Polyhydride. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Liam J. Donnelly
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, The King’s Buildings, Edinburgh EH9 3FJ, U.K
| | - Teresa Faber
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, The King’s Buildings, Edinburgh EH9 3FJ, U.K
| | - Carole A. Morrison
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, The King’s Buildings, Edinburgh EH9 3FJ, U.K
| | - Gary S. Nichol
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, The King’s Buildings, Edinburgh EH9 3FJ, U.K
| | - Stephen P. Thomas
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, The King’s Buildings, Edinburgh EH9 3FJ, U.K
| | - Jason B. Love
- EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, The King’s Buildings, Edinburgh EH9 3FJ, U.K
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29
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Huang M, Wu Z, Krebs J, Friedrich A, Luo X, Westcott SA, Radius U, Marder TB. Ni-Catalyzed Borylation of Aryl Sulfoxides. Chemistry 2021; 27:8149-8158. [PMID: 33851475 PMCID: PMC8252015 DOI: 10.1002/chem.202100342] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Indexed: 12/21/2022]
Abstract
A nickel/N-heterocyclic carbene (NHC) catalytic system has been developed for the borylation of aryl sulfoxides with B2 (neop)2 (neop=neopentyl glycolato). A wide range of aryl sulfoxides with different electronic and steric properties were converted into the corresponding arylboronic esters in good yields. The regioselective borylation of unsymmetric diaryl sulfoxides was also feasible leading to borylation of the sterically less encumbered aryl substituent. Competition experiments demonstrated that an electron-deficient aryl moiety reacts preferentially. The origin of the selectivity in the Ni-catalyzed borylation of electronically biased unsymmetrical diaryl sulfoxide lies in the oxidative addition step of the catalytic cycle, as oxidative addition of methoxyphenyl 4-(trifluoromethyl)phenyl sulfoxide to the Ni(0) complex occurs selectively to give the structurally characterized complex trans-[Ni(ICy)2 (4-CF3 -C6 H4 ){(SO)-4-MeO-C6 H4 }] 4. For complex 5, the isomer trans-[Ni(ICy)2 (C6 H5 )(OSC6 H5 )] 5-I was structurally characterized in which the phenyl sulfinyl ligand is bound via the oxygen atom to nickel. In solution, the complex trans-[Ni(ICy)2 (C6 H5 )(OSC6 H5 )] 5-I is in equilibrium with the S-bonded isomer trans-[Ni(ICy)2 (C6 H5 )(SOC6 H5 )] 5, as shown by NMR spectroscopy. DFT calculations reveal that these isomers are separated by a mere 0.3 kJ/mol (M06/def2-TZVP-level of theory) and connected via a transition state trans-[Ni(ICy)2 (C6 H5 )(η2 -{SO}-C6 H5 )], which lies only 10.8 kcal/mol above 5.
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Affiliation(s)
- Mingming Huang
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Zhu Wu
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Johannes Krebs
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Alexandra Friedrich
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Xiaoling Luo
- Chongqing Key Laboratory of Inorganic Functional MaterialsCollege of ChemistryChongqing Normal UniversityChongqing401331China
| | - Stephen A. Westcott
- Department of Chemistry & BiochemistryMount Allison UniversitySackvilleNB E4L 1G8Canada
| | - Udo Radius
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Todd B. Marder
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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31
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Zhang M, Wu H, Yang J, Huang G. A Computational Mechanistic Analysis of Iridium-Catalyzed C(sp3)–H Borylation Reveals a One-Stone–Two-Birds Strategy to Enhance Catalytic Activity. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00389] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Mei Zhang
- Department of Chemistry, School of Science and Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Hongli Wu
- Department of Chemistry, School of Science and Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Jinjin Yang
- Department of Chemistry, School of Science and Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Genping Huang
- Department of Chemistry, School of Science and Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, Tianjin 300072, People’s Republic of China
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32
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Wen J, Shi Z. From C4 to C7: Innovative Strategies for Site-Selective Functionalization of Indole C-H Bonds. Acc Chem Res 2021; 54:1723-1736. [PMID: 33709705 DOI: 10.1021/acs.accounts.0c00888] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The widespread presence of hydrocarbons makes C-H functionalization an attractive alternative to traditional cross-coupling methods. As indole is an important heteroarene in a plethora of natural products and pharmaceuticals, C-H functionalization of indole moieties has emerged as one of the most important topics in this field. Due to the presence of multiple C-H bonds in indoles, site selectivity is a long-standing challenge. Much effort has been devoted to the C-H functionalization of indoles at the C3 or C2 position, while accessing the benzene core (from C4 to C7) is considerably more challenging.This Account summarizes our recent efforts toward site-selective C-H functionalization of indoles at the benzene core based on innovative strategies. A common method to solve the issue involves the development of directing groups (DGs). Our early studies establish that the installation of the N-P(O)tBu2 group at the N position can produce C7 and C6 arylation products using palladium and copper catalysts, respectively. The developed system can also be extended to direct arylation of indoles at the C5 and C4 positions by installing a pivaloyl group at the C3 position. Further investigation of indoles bearing N-PtBu2 groups shows a more diverse reactivity for C-H functionalizations at the C7 position, including arylation, olefination, acylation, alkylation, silylation, and carbonylation with different coupling partners. Compared to the P(V) DG, the P(III) group can be easily attached to the indole substrates and detached from the products. However, these attractive reactions rely mostly on precious metal catalysts with ligands; this requirement can be a significant limitation, particularly for large-scale syntheses and the necessity of removal of toxic trace metals in pharmaceutical products. We have also uncovered a general strategy for chelation-assisted aromatic C-H borylation just using simple BBr3 under mild conditions, in which the installation of pivaloyl groups at the N1 or C3 position of indoles can selectively deliver the boron species to the unfavorable C7 or C4 positions and allow subsequent C-H borylation without any metal. This transition-metal-free strategy can be extended to synthesize C7 and C4 hydroxylated indoles by boron-mediated directed C-H hydroxylation under mild reaction conditions and with broad functional group compatibility.In this Account, we describe our contributions to this topic since 2015. These studies provide efficient and attractive methods for the divergent synthesis of valuable substituted indoles and insights into the exploration of new strategies for the site-selective C-H functionalization and directives for other important heteroarenes.
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Affiliation(s)
- Jian Wen
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Zhuangzhi Shi
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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33
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Zou Y, Zhang B, Wang L, Zhang H. Benzoic Acid-Promoted C2-H Borylation of Indoles with Pinacolborane. Org Lett 2021; 23:2821-2825. [PMID: 33733795 DOI: 10.1021/acs.orglett.1c00809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A benzoic acid-promoted C2-H borylation of indoles with pinacolborane to afford C2-borylated indoles is developed. Preliminary mechanistic studies indicate BH3-related borane species formed via the decomposition of pinacolborane to be the probable catalyst. This transformation provides a prompt route toward the synthesis of diverse C2-functionalized indoles.
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Affiliation(s)
- Youliang Zou
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Binfeng Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Li Wang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Hua Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
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34
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Zhang G, Li MY, Ye WB, He ZT, Feng CG, Lin GQ. Borylation of Unactivated C(sp 3)-H Bonds with Bromide as a Traceless Directing Group. Org Lett 2021; 23:2948-2953. [PMID: 33764787 DOI: 10.1021/acs.orglett.1c00617] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A palladium-catalyzed alkyl C-H borylation with bromide as a traceless directing group is described, providing a convenient approach to access alkyl boronates bearing a β-all-carbon quaternary stereocenter. The protocol features a broad substrate scope, excellent site selectivity, and good functional group tolerance.
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Affiliation(s)
- Ge Zhang
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Meng-Yao Li
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Wen-Bo Ye
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhi-Tao He
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Chen-Guo Feng
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China.,The Research Center of Chiral Drugs, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Guo-Qiang Lin
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China.,The Research Center of Chiral Drugs, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
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35
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Wang ZJ, Chen X, Wu L, Wong JJ, Liang Y, Zhao Y, Houk KN, Shi Z. Metal-Free Directed C-H Borylation of Pyrroles. Angew Chem Int Ed Engl 2021; 60:8500-8504. [PMID: 33449421 DOI: 10.1002/anie.202016573] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/12/2021] [Indexed: 01/08/2023]
Abstract
Robust strategies to enable the rapid construction of complex organoboronates in selective, practical, low-cost, and environmentally friendly modes remain conspicuously underdeveloped. Here, we develop a general strategy for the site-selective C-H borylation of pyrroles by using only BBr3 directed by pivaloyl groups, avoiding the use of any metal. The site-selectivity is generally dominated by chelation and electronic effects, thus forming diverse C2-borylated pyrroles against the steric effect. The formed products can readily engage in downstream transformations, enabling a step-economic process to access drugs such as Lipitor. DFT calculations (wB97X-D) demonstrate the preferred positional selectivity of this reaction.
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Affiliation(s)
- Zheng-Jun Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Xiangyang Chen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Lei Wu
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Jonathan J Wong
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Yong Liang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Zhuangzhi Shi
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
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36
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Liu Y, Li JL, Liu XG, Wu JQ, Huang ZS, Li Q, Wang H. Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes. Org Lett 2021; 23:1891-1897. [PMID: 33591193 DOI: 10.1021/acs.orglett.1c00309] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Borylated aza-arenes are of great importance in the area of organic synthesis. A radical borylative cyclization of isocyanoarenes with N-heterocyclic carbene borane (NHC-BH3) under metal-free conditions was developed. The reaction allows the efficient assembly of several types of borylated aza-arenes (phenanthridines, benzothiazoles, etc.), which are difficult to access using alternative methods. Mild reaction conditions, a good functional-group tolerance, and generally good efficiencies were observed. The utility of these products is demonstrated, and the mechanism is discussed.
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Affiliation(s)
- Yao Liu
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Ji-Lin Li
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xu-Ge Liu
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jia-Qiang Wu
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhi-Shu Huang
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Qingjiang Li
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Honggen Wang
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
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37
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Wang Z, Chen X, Wu L, Wong JJ, Liang Y, Zhao Y, Houk KN, Shi Z. Metal‐Free Directed C−H Borylation of Pyrroles. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016573] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Zheng‐Jun Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC) School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China
| | - Xiangyang Chen
- Department of Chemistry and Biochemistry University of California Los Angeles CA 90095 USA
| | - Lei Wu
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC) School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China
| | - Jonathan J. Wong
- Department of Chemistry and Biochemistry University of California Los Angeles CA 90095 USA
| | - Yong Liang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC) School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC) School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China
| | - Kendall N. Houk
- Department of Chemistry and Biochemistry University of California Los Angeles CA 90095 USA
| | - Zhuangzhi Shi
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC) School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China
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38
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Sathieshkumar PP, Anand Saibabu MD, Nagarajan R. A Cascade Approach for the Synthesis of 5-(Indol-3-yl)hydantoin: An Application to the Total Synthesis of (±)-Oxoaplysinopsin B. J Org Chem 2021; 86:3730-3740. [PMID: 33599509 DOI: 10.1021/acs.joc.0c02435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A cascade approach to the synthesis of 5-(indol-3-yl)hydantoin framework has been developed by the reaction of indole with glyoxylic acid/pyruvic acid under a deep eutectic solution, (+)-tartaric acid-dimethylurea. N,N'-Dimethylurea from a deep eutectic solution functions as a reactant as well as a solvent mixture. Isolation of the intermediate, 5-hydroxyhydantoin, and its reaction with indole provides the mechanistic evidence for this reaction. This method was successfully applied in the first total synthesis of an alkaloid, (±)-oxoaplysinopsin B, with an overall yield of 48%.
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Affiliation(s)
| | | | - Rajagopal Nagarajan
- School of Chemistry, University of Hyderabad, Hyderabad, Telangana 500046, India
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39
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Willcox DR, Nichol GS, Thomas SP. Borane-Catalyzed C(sp3)–F Bond Arylation and Esterification Enabled by Transborylation. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00282] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Dominic R. Willcox
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, Edinburgh, EH9 3FJ, U.K
| | - Gary S. Nichol
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, Edinburgh, EH9 3FJ, U.K
| | - Stephen P. Thomas
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, Edinburgh, EH9 3FJ, U.K
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40
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Dalton T, Faber T, Glorius F. C-H Activation: Toward Sustainability and Applications. ACS CENTRAL SCIENCE 2021; 7:245-261. [PMID: 33655064 PMCID: PMC7908034 DOI: 10.1021/acscentsci.0c01413] [Citation(s) in RCA: 253] [Impact Index Per Article: 84.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Indexed: 05/14/2023]
Abstract
Since the definition of the "12 Principles of Green Chemistry" more than 20 years ago, chemists have become increasingly mindful of the need to conserve natural resources and protect the environment through the judicious choice of synthetic routes and materials. The direct activation and functionalization of C-H bonds, bypassing intermediate functional group installation is, in abstracto, step and atom economic, but numerous factors still hinder the sustainability of large-scale applications. In this Outlook, we highlight the research areas seeking to overcome the sustainability challenges of C-H activation: the pursuit of abundant metal catalysts, the avoidance of static directing groups, the replacement of metal oxidants, and the introduction of bioderived solvents. We close by examining the progress made in the subfield of aryl C-H borylation from its origins, through highly efficient but precious Ir-based systems, to emerging 3d metal catalysts. The future growth of this field will depend on industrial uptake, and thus we urge researchers to strive toward sustainable C-H activation.
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Affiliation(s)
- Toryn Dalton
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 4048149 Münster, Germany
| | - Teresa Faber
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 4048149 Münster, Germany
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 4048149 Münster, Germany
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41
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Tian YM, Guo XN, Braunschweig H, Radius U, Marder TB. Photoinduced Borylation for the Synthesis of Organoboron Compounds. Chem Rev 2021; 121:3561-3597. [PMID: 33596057 DOI: 10.1021/acs.chemrev.0c01236] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Organoboron compounds have important synthetic value and can be applied in numerous transformations. The development of practical and convenient ways to synthesize boronate esters has thus attracted significant interest. Photoinduced borylations originated from stoichiometric reactions of alkanes and arenes with well-defined metal-boryl complexes. Now, photoredox-initiated borylations, catalyzed by either transition metal or organic photocatalysts, and photochemical borylations with high efficiency have become a burgeoning area of research. In this Focus Review, we summarize research on photoinduced borylations, especially emphasizing recent developments and trends. This includes the photoinduced borylation of arenes, alkanes, aryl/alkyl halides, activated carboxylic acids, amines, alcohols, and so on based on transition metal catalysis, metal-free organocatalysis, and direct photochemical activation. We focus on reaction mechanisms involving single-electron transfer, triplet-energy transfer, and other radical processes.
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Affiliation(s)
- Ya-Ming Tian
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Xiao-Ning Guo
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Todd B Marder
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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Slack ED, Colacot TJ. Understanding the Activation of Air-Stable Ir(COD)(Phen)Cl Precatalyst for C–H Borylation of Aromatics and Heteroaromatics. Org Lett 2021; 23:1561-1565. [PMID: 33546555 DOI: 10.1021/acs.orglett.0c04210] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Eric D. Slack
- Johnson Matthey, 2001 Nolte Drive, West Deptford, New Jersey 08066, United States
| | - Thomas J. Colacot
- Johnson Matthey, 2001 Nolte Drive, West Deptford, New Jersey 08066, United States
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Pan Z, Liu L, Xu S, Shen Z. Ligand-free iridium-catalyzed regioselective C-H borylation of indoles. RSC Adv 2021; 11:5487-5490. [PMID: 35423099 PMCID: PMC8694714 DOI: 10.1039/d0ra10211c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 01/17/2021] [Indexed: 01/03/2023] Open
Abstract
We herein report a ligand-free Ir-catalyzed C-H borylation of N-acyl protected indoles. This simple protocol could tolerate a variety of functional groups, affording C3 borylated indoles in good yields with excellent regioselectivities. We also demonstrated that the current method is amenable to gram-scale borylation and the C-B bonds could be easily converted to C-C and C-heteroatom bonds.
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Affiliation(s)
- Zilong Pan
- College of Chemical Engineering, Zhejiang University of Technology Hangzhou 310014 China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Science, Suzhou Research Institute, Lanzhou Institute of Chemical Physics, Chinese Academy of Science Lanzhou 730000 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Luhua Liu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Science, Suzhou Research Institute, Lanzhou Institute of Chemical Physics, Chinese Academy of Science Lanzhou 730000 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Senmiao Xu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Science, Suzhou Research Institute, Lanzhou Institute of Chemical Physics, Chinese Academy of Science Lanzhou 730000 China
| | - Zhenlu Shen
- College of Chemical Engineering, Zhejiang University of Technology Hangzhou 310014 China
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Wu J, Qian B, Lu L, Yang H, Shang Y, Zhang J. Access to the C2 C–H olefination, alkylation and deuteration of indoles by rhodium( iii) catalysis: an opportunity for diverse syntheses. Org Chem Front 2021. [DOI: 10.1039/d1qo00133g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A concise approach for a diversity-oriented synthesis via regioselective C2 C–H olefination, alkylation, and deuteration of indoles by Rh(iii) catalysis is described.
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Affiliation(s)
- Jiaping Wu
- Key Laboratory of Functional Molecular Solids (Ministry of Education)
- Anhui Key Laboratory of Molecular Based Materials
- College of Chemistry and Materials Science
- Anhui Normal University
- Wuhu 241002
| | - Baiyang Qian
- Key Laboratory of Functional Molecular Solids (Ministry of Education)
- Anhui Key Laboratory of Molecular Based Materials
- College of Chemistry and Materials Science
- Anhui Normal University
- Wuhu 241002
| | - Lili Lu
- Key Laboratory of Functional Molecular Solids (Ministry of Education)
- Anhui Key Laboratory of Molecular Based Materials
- College of Chemistry and Materials Science
- Anhui Normal University
- Wuhu 241002
| | - Haitao Yang
- Key Laboratory of Functional Molecular Solids (Ministry of Education)
- Anhui Key Laboratory of Molecular Based Materials
- College of Chemistry and Materials Science
- Anhui Normal University
- Wuhu 241002
| | - Yongjia Shang
- Key Laboratory of Functional Molecular Solids (Ministry of Education)
- Anhui Key Laboratory of Molecular Based Materials
- College of Chemistry and Materials Science
- Anhui Normal University
- Wuhu 241002
| | - Jitan Zhang
- Key Laboratory of Functional Molecular Solids (Ministry of Education)
- Anhui Key Laboratory of Molecular Based Materials
- College of Chemistry and Materials Science
- Anhui Normal University
- Wuhu 241002
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45
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Wang J, Xiao R, Zheng K, Qian L. Mechanistic and chemoselective insights on sp 3- and sp 2-C–H bond aminations: Fe- vs. Ir-based catalysis. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00682g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The mechanisms of Fe- and Ir-catalyzed sp3- and sp2-C–H bond aminations of a styryl substrate have been studied using the BPW91 method, with an emphasis on the origin of sp3-to-sp2-C–H amination chemoselectivity.
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Affiliation(s)
- Juping Wang
- School of Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou
- P. R. China
| | - Rongxing Xiao
- School of Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou
- P. R. China
| | - Kangcheng Zheng
- School of Chemistry
- Sun Yat-sen University
- Guangzhou
- P. R. China
| | - Li Qian
- School of Pharmacy
- Youjiang Medical University for Nationalities
- P. R. China
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46
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Kumar P, Nagtilak PJ, Kapur M. Transition metal-catalyzed C–H functionalizations of indoles. NEW J CHEM 2021. [DOI: 10.1039/d1nj01696b] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This review summarises a wide range of transformations on the indole skeleton, including arylation, alkenylation, alkynylation, acylation, nitration, borylation, and amidation, using transition-metal catalyzed C–H functionalization as the key step.
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Affiliation(s)
- Pravin Kumar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, MP, India
| | - Prajyot Jayadev Nagtilak
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, MP, India
| | - Manmohan Kapur
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, MP, India
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Lipshultz JM, Fu Y, Liu P, Radosevich AT. Organophosphorus-catalyzed relay oxidation of H-Bpin: electrophilic C-H borylation of heteroarenes. Chem Sci 2020; 12:1031-1037. [PMID: 34163869 PMCID: PMC8179051 DOI: 10.1039/d0sc05620k] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A nontrigonal phosphorus triamide (1, P{N[o-NMe-C6H4]2}) is shown to catalyze C–H borylation of electron-rich heteroarenes with pinacolborane (HBpin) in the presence of a mild chloroalkane reagent. C–H borylation proceeds for a range of electron-rich heterocycles including pyrroles, indoles, and thiophenes of varied substitution. Mechanistic studies implicate an initial P–N cooperative activation of HBpin by 1 to give P-hydrido diazaphospholene 2, which is diverted by Atherton–Todd oxidation with chloroalkane to generate P-chloro diazaphospholene 3. DFT calculations suggest subsequent oxidation of pinacolborane by 3 generates chloropinacolborane (ClBpin) as a transient electrophilic borylating species, consistent with observed substituent effects and regiochemical outcomes. These results illustrate the targeted diversion of established reaction pathways in organophosphorus catalysis to enable a new mode of main group-catalyzed C–H borylation. A nontrigonal phosphorus triamide (1, P{N[o-NMe-C6H4]2}) is shown to catalyze C–H borylation of electron-rich heteroarenes with pinacolborane (HBpin) in the presence of a mild chloroalkane reagent.![]()
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Affiliation(s)
- Jeffrey M Lipshultz
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Yue Fu
- Department of Chemistry, University of Pittsburgh 219 Parkman Avenue Pittsburgh PA 15260 USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh 219 Parkman Avenue Pittsburgh PA 15260 USA
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
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Tian YM, Guo XN, Krummenacher I, Wu Z, Nitsch J, Braunschweig H, Radius U, Marder TB. Visible-Light-Induced Ni-Catalyzed Radical Borylation of Chloroarenes. J Am Chem Soc 2020; 142:18231-18242. [PMID: 33026223 DOI: 10.1021/jacs.0c08834] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A highly selective and general photoinduced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes is reported. This photoinduced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]•- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle.
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Affiliation(s)
- Ya-Ming Tian
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Xiao-Ning Guo
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Zhu Wu
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jörn Nitsch
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Todd B Marder
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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