1
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Peng Y, Wang G, Klare HFT, Oestreich M. Ring Contraction of Saturated Cyclic Amines and Rearrangement of Acyclic Amines Through Their Corresponding Hydroxylamines. Angew Chem Int Ed Engl 2024; 63:e202410483. [PMID: 38953245 DOI: 10.1002/anie.202410483] [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: 06/04/2024] [Revised: 06/24/2024] [Accepted: 07/02/2024] [Indexed: 07/03/2024]
Abstract
Compared to modifications at the molecular periphery, skeletal adjustments present greater challenges. Within this context, skeletal rearrangement technology stands out for its significant advantages in rapidly achieving structural diversity. Yet, the development of this technology for ring contraction of saturated cyclic amines remains exceedingly rare. While most existing methods rely on specific substitution patterns to achieve ring contraction, there is a persistent demand for a more general strategy for substitution-free cyclic amines. To address this issue, we report a B(C6F5)3-catalyzed skeletal rearrangement of hydroxylamines with hydrosilanes. This methodology, when combined with the N-hydroxylation of amines, enables the regioselective ring contraction of cyclic amines and proves equally effective for rapid reorganization of acyclic amine skeletons. By this, the direct scaffold hopping of drug molecules and the strategic deletion of carbon atoms are achieved in a mild manner. Based on mechanistic experiments and density functional theory calculations, a possible mechanism for this process is proposed.
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Affiliation(s)
- Yi Peng
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Guoqiang Wang
- Institute of Theoretical and Computational Chemistry School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P.R. China
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
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2
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Gao H, Kwon S, Kwon HY, Irran E, Klare HFT, Baik MH, Oestreich M. Cationic Bis(hydrosilane)-Coinage-Metal Complexes: Synthesis, Characterization, and Use as Catalysts for Outer-Sphere C=O Hydrosilylation Not Involving Metal Hydrides. Angew Chem Int Ed Engl 2024; 63:e202409582. [PMID: 38923659 DOI: 10.1002/anie.202409582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/10/2024] [Accepted: 06/24/2024] [Indexed: 06/28/2024]
Abstract
The preparation of cationic bis(hydrosilane)-coinage-metal complexes by chloride abstraction from the neutral metal chloride precursors with Na[BArF 4] is described. Unlike previously reported hydrosilane-stabilized copper and silver complexes, the presented complexes are cationic and feature two bidentate (ortho-silylphenyl)phosphine ligands. These complexes were fully characterized by NMR spectroscopy and X-ray diffraction analysis, revealing that both Si-H bonds are activated by the Lewis acidic cationic metal center. The new complexes were found to be effective in catalytic carbonyl hydrosilylation, leading to the corresponding silyl ethers under mild conditions without the addition of an external base. Combined mechanistic control experiments and quantum chemical calculations support an ionic outer-sphere mechanism, in which a neutral metal alkoxide species instead of a metal hydride is the key intermediate that interacts with the silylcarboxonium ion to generate the silyl ether.
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Affiliation(s)
- Haopeng Gao
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Seongyeon Kwon
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS) & Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hyuk-Yong Kwon
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS) & Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Elisabeth Irran
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Mu-Hyun Baik
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS) & Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
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3
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Li H, Han B, Wang R, Li W, Zhang W, Fu X, Fang H, Ma F, Wang Z, Zhang J. Photochemical conversion of CO to C1 and C2 products mediated by porphyrin rhodium(II) metallo-radical complexes. Nat Commun 2024; 15:7724. [PMID: 39231963 PMCID: PMC11374781 DOI: 10.1038/s41467-024-50253-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 07/03/2024] [Indexed: 09/06/2024] Open
Abstract
Unimolecular reduction and bimolecular reductive coupling of carbon monoxide (CO) represent important ways to synthesize organic feedstocks. Reductive activation of CO through open-shell pathways, though rare, can help overcome the barriers of many traditional organometallic elementary reactions that are hard to achieve. Herein we successfully achieve the unimolecular reduction of CO to (TPP)RhCH2OSiR1R2R3 (TPP = 5,10,15,20-tetraphenylporphyrin), and the release of products CH3OSiR1R2R3, TEMPO-CH2OSiR1R2R3 and BrCH2OSiR1R2R3 in near-quantitative yield under visible light (420-780 nm), which involves radical formation from Rh-C bond homolysis. Bimolecular CO reductive coupling products, (TPP)RhCOCH2OSiR1R2R3, are then obtained via a radical mechanism. Subsequent treatment with n-propylamine, BrCCl3 or TEMPO under thermal or photochemical conditions afford small-molecule bimolecular reductive coupling products. To the best of our knowledge, homogeneous systems which reductively couple CO under photochemical conditions have not been reported before. Here, the use of an open-shell transition metal complex, that delivers more than one kind of small-molecule CO reductive coupling products bearing different functional groups, provides opportunities for useful CO reductive transformations.
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Affiliation(s)
- Hongsen Li
- School of Pharmacy, Binzhou Medical University, Yantai, 264003, China
| | - Boao Han
- School of Pharmacy, Binzhou Medical University, Yantai, 264003, China
| | - Rongyi Wang
- School of Pharmacy, Binzhou Medical University, Yantai, 264003, China
| | - Wentao Li
- Beijing National Laboratory for Molecular Sciences, State Key Lab of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Wentao Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Lab of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Xuefeng Fu
- Beijing National Laboratory for Molecular Sciences, State Key Lab of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Huayi Fang
- School of Materials Science and Engineering, Tianjin Key Lab for Rare Earth Materials and Applications, Nankai University, Tianjin, 300350, China
| | - Fuqiu Ma
- Yantai Research Institute of Harbin Engineering University, Yantai, 264003, China
| | - Zikuan Wang
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany.
| | - Jiajing Zhang
- School of Pharmacy, Binzhou Medical University, Yantai, 264003, China.
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Boegli MC, Coffinet A, Bijani C, Simonneau A. Seven-Coordinate Group 6 Metal Hydrides Obtained by H 2 Activation at B(C 6F 5) 3 Adducts of N 2 Complexes: Frustrated Lewis Pair-Type Reactivity of The B-N Linkage. Chem Asian J 2024; 19:e202400451. [PMID: 38864406 DOI: 10.1002/asia.202400451] [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: 04/23/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 06/13/2024]
Abstract
The adducts 2M,R of general formula trans-[(L)M{R2P(CH2)2PR2}2{N2B(C6F5)3}] (L=ø or N2, M=Mo or W, R=Et or Ph), formed from Lewis acid-base pairing of B(C6F5)3 to a dinitrogen ligand of zero-valent group 6 bis(phosphine) complexes trans-[M{R2P(CH2)2PR2}2(N2)2] are shown to react with dihydrogen to afford hepta-coordinated bis(hydride) complexes [M(H)2{R2P(CH2)2PR2}{N2B(C6F5)3}] 3M,R which feature the rare ability to activate both dinitrogen and dihydrogen at a single metal center, except in the case where M=Mo and R=Ph for which fast precipitation of insoluble [Mo(H)4(dppe)2] (dppe=1,2-bis(diphenylphosphino)ethane) occurs. The frustrated Lewis pair (FLP)-related reactivity of the B-N linkage in compounds 3W,R was explored and led to distal N functionalization without involvement of the hydride ligands. It is shown in one example that the resulting bis(hydride) diazenido compounds may also be obtained through a sequence involving first FLP-type N-functionalization followed by oxidative addition of H2. Those oily compounds were found to have limited stability in solution or in their isolated states. Finally, treatment of 3W,Et with the Lewis base N,N-dimethylaminopyridine (DMAP) affords the simple but unknown bis(hydride)-dinitrogen species [W(H)2(depe)2(N2)] 11Et (depe=1,2-bis(diethylphosphino)ethane) which direct, selective formation from trans-[W(N2)2(depe)2] is not possible.
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Affiliation(s)
- Marie-Christine Boegli
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Anaïs Coffinet
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Christian Bijani
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Antoine Simonneau
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
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Wieprecht N, Krummenacher I, Wüst L, Michel M, Fuchs S, Nees S, Härterich M, Braunschweig H. The forgotten borole: synthesis, properties and reactivity of a 1-boraindene. Chem Sci 2024; 15:12496-12501. [PMID: 39118599 PMCID: PMC11304793 DOI: 10.1039/d4sc03817g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 06/29/2024] [Indexed: 08/10/2024] Open
Abstract
The chemistry of unsaturated boron heterocycles, including five-membered boroles, continues to attract substantial interest. Herein, we report the synthesis of 1,2,3-triphenyl-1-boraindene, a benzene-fused borole, and examine its Lewis acidic, electrophilic, and antiaromatic properties relative to non-fused and bis-benzannulated boroles (9-borafluorenes). Reactivity studies with organic azides reveal that the boraindene behaves similarly to other boroles, undergoing ring expansion to a BN-naphthalene through insertion of a nitrogen atom.
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Affiliation(s)
- Nele Wieprecht
- 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
| | - Ivo Krummenacher
- 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
| | - Leonie Wüst
- 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
| | - Maximilian Michel
- 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
| | - Sonja Fuchs
- 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
| | - Samuel Nees
- 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
| | - Marcel Härterich
- 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
| | - Holger Braunschweig
- 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
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Grochowska-Tatarczak M, Koteras K, Kazimierczuk K, Malinowski PJ. Hydrosilylation of Olefins Activated on Highly Lewis-Acidic Calcium Cation. Chemistry 2024:e202401322. [PMID: 38660917 DOI: 10.1002/chem.202401322] [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: 04/03/2024] [Accepted: 04/22/2024] [Indexed: 04/26/2024]
Abstract
The report introduces simple yet highly reactive calcium salt, Ca[Al(ORF)4]2 (RF=C(CF3)3), 1, which effectively catalyses olefin hydrosilylation through an unusual mechanism involving the activation of the alkene molecule. Upon dissolution in o-difluorobenzene (oDFB), 1 forms a highly Lewis acidic [Ca(oDFB)6]2+ complex. Our DFT calculations reveal that fluoride ion affinity is comparable to SbF5. Reactivity tests show that it effectively catalyses the hydrosilylation of olefins with high regioselectivity, also in reactions involving sterically demanding substrates like (iPr)3SiH or tetrasubstituted olefins. Experimental and computational results point to the mechanism where the olefin molecule forms a complex with Ca2+, which significantly facilitates the attack of H-SiR3 on the C=C double bond.
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Affiliation(s)
| | - K Koteras
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-093, Warsaw, Poland
| | - K Kazimierczuk
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-093, Warsaw, Poland
| | - P J Malinowski
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-093, Warsaw, Poland
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7
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Su X, Wang Y, Feng Q, Sun J. Heterodifunctionalization of Electron-Rich Alkynes Catalyzed by in Situ Generated Silylium Ions. Org Lett 2024; 26:421-426. [PMID: 38166166 DOI: 10.1021/acs.orglett.3c04208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Silylium ions are versatile Lewis acids in organic synthesis. While they have been well-known for the activation of σ donors, catalysis initiated by the activation of π donors remains underdeveloped, particularly for alkynes. Herein, we demonstrate an example of silylium-catalyzed alkyne heterodifunctionalization. The silylium ion generated in situ from HNTf2 and the silyl reagent serve as superior catalysts in the efficient silylphosphination and silylcyanation of electron-rich alkynes with excellent regio- and stereoselectivity. The compatibility of this protocol with strongly coordinating ligands (Ph2P and CN) not only complements the metal-catalyzed systems but also expands the scope of silylium-catalyzed reactions.
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Affiliation(s)
- Xiang Su
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, China
| | - Yong Wang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
| | - Qiang Feng
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
| | - Jianwei Sun
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
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Guo J, Liu S, Jing J, Fan Y, Fu Y, Liu S, Wang W, Gao L, Song Z. Controllable Si-C Bond Formation from Trihydrosilanes En Route to Synthesis of 1,4-Azasilinanes with Diverse Silyl Functionalities. Org Lett 2023; 25:7428-7433. [PMID: 37791679 DOI: 10.1021/acs.orglett.3c03014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
A B(C6F5)3-catalyzed controllable inter/intra-/intermolecular Si-C bond formation process has been developed from trihydrosilane and dienamide with alkenes, anilines, or aryl iodides. A variety of 1,4-azasilinanes have been generated with diverse exo-cyclic heteroleptic disubstitutions on silicon, thereby expanding the range of silaazacyclic rings available for the discovery of silicon-containing drugs.
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Affiliation(s)
- Jiawei Guo
- Shaanxi Key Laboratory of Catalysis, School of Chemistry & Environmental Science, Shaanxi University of Technology, Hanzhong, 723001, People's Republic of China
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Shunfa Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Jun Jing
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Yu Fan
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Yingdong Fu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Shiyang Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Wanshu Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Lu Gao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Zhenlei Song
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
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Rubinsztajn S, Chojnowski J, Mizerska U. Tris(pentafluorophenyl)borane-catalyzed Hydride Transfer Reactions in Polysiloxane Chemistry-Piers-Rubinsztajn Reaction and Related Processes. Molecules 2023; 28:5941. [PMID: 37630197 PMCID: PMC10459531 DOI: 10.3390/molecules28165941] [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: 06/21/2023] [Revised: 07/28/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
Tris(pentafluorophenyl)borane (TPFPB) is a unique Lewis acid that catalyzes the condensation between hydrosilanes (Si-H) and alkoxysilanes (Si-OR), leading to the formation of siloxane bonds (Si-OSi) with the release of hydrocarbon (R-H) as a byproduct-the so-called Piers-Rubinsztajn reaction. The analogous reactions of hydrosilanes with silanols (Si-OH), alcohols (R-OH), ethers (R-OR') or water in the presence of TPFPB leads to the formation of a siloxane bond, alkoxysilane (Si-OR or Si-OR') or silanol (Si-OH), respectively. The above processes, often referred to as Piers-Rubinsztajn reactions, provide new synthetic tools for the controlled synthesis of siloxane materials under mild conditions with high yields. The common feature of these reactions is the TPFPB-mediated hydride transfer from silicon to carbon or hydrogen. This review presents a summary of 20 years of research efforts related to this field, with a focus on new synthetic methodologies leading to numerous previously difficult to synthesize well-defined siloxane oligomers, polymers and copolymers of a complex structure and potential applications of these new materials. In addition, the mechanistic aspects of the recently discovered reactions involving hydride transfer from silicon to silicon are discussed in more detail.
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Affiliation(s)
- Slawomir Rubinsztajn
- Centre of Molecular and Macromolecular Studies of Polish Academy of Sciences, Sienkiewicza 112, 90-636 Lodz, Poland;
| | - Julian Chojnowski
- Centre of Molecular and Macromolecular Studies of Polish Academy of Sciences, Sienkiewicza 112, 90-636 Lodz, Poland;
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10
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Sarcevic J, Heitkemper T, Ruth PN, Naß L, Kubis M, Stalke D, Sindlinger CP. A donor-supported silavinylidene and silylium ylides: boroles as a flexible platform for versatile Si(ii) chemistry. Chem Sci 2023; 14:5148-5159. [PMID: 37206392 PMCID: PMC10189903 DOI: 10.1039/d3sc00808h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/30/2023] [Indexed: 09/22/2024] Open
Abstract
Electron-deficient, anti-aromatic 2,5-disilyl boroles are shown to be a flexibly adaptive molecular platform with regards to SiMe3 mobility in their reaction with the nucleophilic donor-stabilised precursor dichloro silylene SiCl2(IDipp). Depending on the substitution pattern, selective formation of two fundamentally different products of rivalling formation pathways is achieved. Formal addition of the dichlorosilylene gives the 5,5-dichloro-5-sila-6-borabicyclo[2.1.1]hex-2-ene derivatives. Under kinetically controlled conditions, SiCl2(IDipp) induces 1,3-trimethylsilyl migration and adds exocyclically to the generated carbene fragment giving an NHC-supported silylium ylide. In some cases interconversion between these compound classes was triggered by temperature or NHC-addition. Reduction of silaborabicyclo[2.1.1]hex-2-ene derivatives under forcing conditions gave clean access to recently described nido-type cluster Si(ii) half-sandwich complexes of boroles. Reduction of a NHC-supported silylium ylide gave an unprecedented NHC-supported silavinylidene which rearranges to the nido-type cluster at elevated temperatures.
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Affiliation(s)
- Julijan Sarcevic
- Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70169 Stuttgart Germany
| | - Tobias Heitkemper
- Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70169 Stuttgart Germany
| | - Paul Niklas Ruth
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | - Leonard Naß
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | - Maximilian Kubis
- Institut für Anorganische Chemie, RWTH Aachen University Landoltweg 1a 52074 Aachen Germany
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | - Christian P Sindlinger
- Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70169 Stuttgart Germany
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11
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Csókás D, Gupta R, Prasad PK, Goh KKK, Young RD. Insights into the Mechanism of Aluminum-Catalyzed Halodefluorination. J Org Chem 2023; 88:4397-4404. [PMID: 36926911 DOI: 10.1021/acs.joc.2c03005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Aluminum has been reported to catalyze halodefluorination reactions, where aliphatic fluorine is substituted with a heavier halogen. Although it is known that stoichiometric aluminum halide can perform this reaction, the role of catalytic aluminum halide and organyl alane reagents is not well understood. We investigate the mechanism of the halodefluorination reaction using catalytic aluminum halide and stoichiometric trimethylsilyl halide. We explore the use of B(C6F5)3 as a catalyst to benchmark pathways where aluminum acts either as a Lewis acid catalyst in cooperation with trimethylsilyl halide or as an independent halodefluorination reagent which is subsequently regenerated by trimethylsilyl halide. Computational and experimental results indicate that aluminum acts as an independent halodefluorination reagent and that reactivity trends observed between different halide reagents can be attributed to relative barriers in halide delivery to the organic fragment, which is the rate-limiting step in both the aluminum halide- and B(C6F5)3-catalyzed pathways.
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Affiliation(s)
- Dániel Csókás
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Richa Gupta
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Pragati K Prasad
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Kelvin K K Goh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Rowan D Young
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia 4072
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12
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Diab M, Jaiswal K, Bawari D, Dobrovetsky R. The Chemistry of [1,1′‐bis(
o‐
Carboranyl)]Borane η
2
‐
σ‐
Silane Adduct. Isr J Chem 2023. [DOI: 10.1002/ijch.202300010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Affiliation(s)
- Mohanad Diab
- School of Chemistry Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University Department Tel Aviv 69978 Israel
| | - Kuldeep Jaiswal
- School of Chemistry Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University Department Tel Aviv 69978 Israel
| | - Deependra Bawari
- School of Chemistry Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University Department Tel Aviv 69978 Israel
| | - Roman Dobrovetsky
- School of Chemistry Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University Department Tel Aviv 69978 Israel
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13
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Peng Y, Oestreich M. B(C 6 F 5 ) 3 -Catalyzed Regioselective Ring Opening of Cyclic Amines with Hydrosilanes. Chemistry 2023; 29:e202203721. [PMID: 36448647 DOI: 10.1002/chem.202203721] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/02/2022]
Abstract
Opening the ring of cyclic amines by regioselective fission of one of the carbon-nitrogen bonds greatly expands the repertoire of available nitrogen-containing skeletons. Unlike approaches starting from cyclic tertiary amines, methods that can directly open secondary amines are still scarce. The present work discloses an efficient reductive ring opening of either of these cyclic amines using PhSiH3 under B(C6 F5 )3 catalysis. By this, the direct transformation of unstrained cyclic amines into the corresponding acyclic amines is achieved in a simple one-pot operation. A stepwise mechanism proceeding through the intermediacy of silylammonium ions followed by reductive cleavage of a carbon-nitrogen bond was experimentally verified.
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Affiliation(s)
- Yi Peng
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
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14
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Undirected C-H Bond Activation in Aluminium Hydrido Enaminonates. Molecules 2023; 28:molecules28052137. [PMID: 36903381 PMCID: PMC10004653 DOI: 10.3390/molecules28052137] [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: 02/08/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
Two new aluminium hydrido complexes were synthesized by reacting AlH3 with the enaminone ligand N-(4,4,4-trifluorobut-1-en-3-on)-6,6,6-trifluoroethylamine (HTFB-TFEA) in different molar ratios to obtain mono- and di-hydrido-aluminium enaminonates. Both air and moisture sensitive compounds could be purified via sublimation under reduced pressure. The spectroscopic analysis and structural motif of the monohydrido compound [H-Al(TFB-TBA)2] (3) showed a monomeric 5-coordinated Al(III) centre bearing two chelating enaminone units and a terminal hydride ligand. However, the dihydrido compound exhibited a rapid C-H bond activation and C-C bond formation in the resulting compound [(Al-TFB-TBA)-HCH2] (4a), which was confirmed by single crystal structural data. The intramolecular hydride shift involving the migration of a hydride ligand from aluminium centre to the alkenyl carbon of the enaminone ligand was probed and verified by multi-nuclear spectral studies (1H,1H NOESY, 13C, 19F, and 27Al NMR).
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15
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Gilmer J, Bolte M, Virovets A, Lerner HW, Fantuzzi F, Wagner M. A Hydride-Substituted Homoleptic Silylborate: How Similar is it to its Diborane(6)-Dianion Isostere? Chemistry 2023; 29:e202203119. [PMID: 36210643 PMCID: PMC10100083 DOI: 10.1002/chem.202203119] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Indexed: 11/05/2022]
Abstract
The B-nucleophilic 9H-9-borafluorene dianion reacts with 9-chloro-9-silafluorene to afford air- and moisture-stable silylborate salts M[Ar2 (H)B-Si(H)Ar2 ] (M[HBSiH], M=Li, Na). Li[HBSiH] and Me3 SiCl give the B-pyridine adduct Ar2 (py)B-Si(H)Ar2 ((py)BSiH) or the chlorosilane Li[Ar2 (H)B-Si(Cl)Ar2 ] (Li[HBSiCl]) in C6 H6 -pyridine or THF. In both cases, the first step is H- abstraction at the B center. The resulting free borane subsequently binds a py or thf ligand. While the py adduct is stable at room temperature, the thf adduct undergoes a 1,2-H shift via the cyclic B(μ-H)Si intermediate BHSi, which is afterwards attacked at the Si atom by a Cl- ion to give Li[HBSiCl]. DFT calculations were employed to support the proposed reaction mechanism and to characterize the electronic structure of BHSi. Treatment of Li[HBSiCl] with the N-heterocyclic carbene IMe introduces the neutral donor at the Si atom and leads to Ar2 (H)B-Si(IMe)Ar2 (HBSi(IMe)), a donor-acceptor-stabilized silylene.
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Affiliation(s)
- Jannik Gilmer
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Alexander Virovets
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of Kent, Park Wood Rd, Canterbury, CT2 7NH, UK
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
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16
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Jiang HJ, Simon HDA, Irran E, Klare HFT, Oestreich M. Experimental Mechanistic Analysis of Carbonyl Hydrosilylation Catalyzed by Abu-Omar’s Rhenium(V) Oxo Complex. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Hua-Jie Jiang
- Institut für Chemie, Technische Universitat Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Hendrik D. A. Simon
- Institut für Chemie, Technische Universitat Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Elisabeth Irran
- Institut für Chemie, Technische Universitat Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Hendrik F. T. Klare
- Institut für Chemie, Technische Universitat Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universitat Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
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17
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Guzmán J, Urriolabeitia A, Padilla M, García-Orduña P, Polo V, Fernández-Alvarez FJ. Mechanism Insights into the Iridium(III)- and B(C 6F 5) 3-Catalyzed Reduction of CO 2 to the Formaldehyde Level with Tertiary Silanes. Inorg Chem 2022; 61:20216-20221. [PMID: 36472385 PMCID: PMC10468102 DOI: 10.1021/acs.inorgchem.2c03330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Indexed: 12/12/2022]
Abstract
The catalytic system [Ir(CF3CO2)(κ2-NSiMe)2] [1; NSiMe = (4-methylpyridin-2-yloxy)dimethylsilyl]/B(C6F5)3 promotes the selective reduction of CO2 with tertiary silanes to the corresponding bis(silyl)acetal. Stoichiometric and catalytic studies evidenced that species [Ir(CF3COO-B(C6F5)3)(κ2-NSiMe)2] (3), [Ir(κ2-NSiMe)2][HB(C6F5)3] (4), and [Ir(HCOO-B(C6F5)3)(κ2-NSiMe)2] (5) are intermediates of the catalytic process. The structure of 3 has been determined by X-ray diffraction methods. Theoretical calculations show that the rate-limiting step for the 1/B(C6F5)3-catalyzed hydrosilylation of CO2 to bis(silyl)acetal is a boron-promoted Si-H bond cleavage via an iridium silylacetal borane adduct.
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Affiliation(s)
- Jefferson Guzmán
- Facultad
de Ciencias, Departamento de Química Inorgánica, Instituto
de Síntesis Química y Catálisis Homogénea, Universidad de Zaragoza, CSIC, Zaragoza 50009, Spain
| | - Asier Urriolabeitia
- Facultad
de Ciencias, Departamento de Química Física, BIFI, Universidad de Zaragoza, Zaragoza 50009, Spain
| | - Marina Padilla
- Facultad
de Ciencias, Departamento de Química Inorgánica, Instituto
de Síntesis Química y Catálisis Homogénea, Universidad de Zaragoza, CSIC, Zaragoza 50009, Spain
| | - Pilar García-Orduña
- Facultad
de Ciencias, Departamento de Química Inorgánica, Instituto
de Síntesis Química y Catálisis Homogénea, Universidad de Zaragoza, CSIC, Zaragoza 50009, Spain
| | - Víctor Polo
- Facultad
de Ciencias, Departamento de Química Física, BIFI, Universidad de Zaragoza, Zaragoza 50009, Spain
| | - Francisco J. Fernández-Alvarez
- Facultad
de Ciencias, Departamento de Química Inorgánica, Instituto
de Síntesis Química y Catálisis Homogénea, Universidad de Zaragoza, CSIC, Zaragoza 50009, Spain
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18
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Obi AD, Dickie DA, Tiznado W, Frenking G, Pan S, Gilliard RJ. A Multidimensional Approach to Carbodiphosphorane–Bismuth Coordination Chemistry: Cationization, Redox-Flexibility, and Stabilization of a Crystalline Bismuth Hydridoborate. Inorg Chem 2022; 61:19452-19462. [DOI: 10.1021/acs.inorgchem.2c03337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Akachukwu D. Obi
- Department of Chemistry, University of Virginia, 409 McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, United States
| | - Diane A. Dickie
- Department of Chemistry, University of Virginia, 409 McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, United States
| | - William Tiznado
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, Santiago 8320000, Chile
| | - Gernot Frenking
- Philipps-Universität Marburg Hans-Meerwein-Straße, 35032 Marburg, Germany
| | - Sudip Pan
- Philipps-Universität Marburg Hans-Meerwein-Straße, 35032 Marburg, Germany
| | - Robert J. Gilliard
- Department of Chemistry, University of Virginia, 409 McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, United States
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19
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Akram MO, Tidwell JR, Dutton JL, Martin CD. Tris(ortho-carboranyl)borane: An Isolable, Halogen-Free, Lewis Superacid. Angew Chem Int Ed Engl 2022; 61:e202212073. [PMID: 36135949 PMCID: PMC9828388 DOI: 10.1002/anie.202212073] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Indexed: 01/12/2023]
Abstract
The synthesis of tris(ortho-carboranyl)borane (BoCb3 ), a single site neutral Lewis superacid, in one pot from commercially available materials is achieved. The high fluoride ion affinity (FIA) confirms its classification as a Lewis superacid and the Gutmann-Beckett method as well as adducts with Lewis bases indicate stronger Lewis acidity over the widely used fluorinated aryl boranes. The electron withdrawing effect of ortho-carborane and lack of pi-delocalization of the LUMO rationalize the unusually high Lewis acidity. Catalytic studies indicate that BoCb3 is a superior catalyst for promoting C-F bond functionalization reactions than tris(pentafluorophenyl)borane [B(C6 F5 )3 ].
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Affiliation(s)
- Manjur O. Akram
- Department of Chemistry and BiochemistryBaylor UniversityOne Bear Place #97348WacoTX 76798USA
| | - John R. Tidwell
- Department of Chemistry and BiochemistryBaylor UniversityOne Bear Place #97348WacoTX 76798USA
| | - Jason L. Dutton
- Department of Biochemistry and ChemistryLa Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVictoria3086Australia
| | - Caleb D. Martin
- Department of Chemistry and BiochemistryBaylor UniversityOne Bear Place #97348WacoTX 76798USA
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20
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Zhu H, Hiruta S, Demirci A, Kim S, Hoshino N, Akutagawa T, Mitsuishi M. Effects of Hydride Transfer Ring-Opening Reaction on B(C 6F 5) 3 Catalyzed Polymerization of D 4H Cyclosiloxane and Dialkoxysilanes toward Thermally Stable Silsesquioxane–Siloxane Hybrid Materials. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Huie Zhu
- Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Shogo Hiruta
- Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Ali Demirci
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Soyeon Kim
- Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Norihisa Hoshino
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Tomoyuki Akutagawa
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Masaya Mitsuishi
- Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
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21
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Ríos P, Conejero S, Fernández I. Bonding Situation of σ-E-H Complexes in Transition Metal and Main Group Compounds. Chemistry 2022; 28:e202201920. [PMID: 35900796 PMCID: PMC9804526 DOI: 10.1002/chem.202201920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Indexed: 01/05/2023]
Abstract
The ambiguous bonding situation of σ-E-H (E=Si, B) complexes in transition metal compounds has been rationalized by means of Density Functional Theory calculations. To this end, the combination of the Energy Decomposition Analysis (EDA) method and its Natural Orbital for Chemical Valance (NOCV) extension has been applied to representative complexes described in the literature where the possible η1 versus η2 coordination mode is not unambiguously defined. Our quantitative analyses, which complement previous data based on the application of the Quantum Theory of Atoms in Molecules (QTAIM) approach, indicate that there exists a continuum between genuine η1 and η2 modes depending mainly on the strength of the backdonation. Finally, we also applied this EDA-NOCV approach to related main-group species where the backdonation is minimal.
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Affiliation(s)
- Pablo Ríos
- Instituto de Investigaciones Químicas (IIQ)Departamento de Química InorgánicaCentro de Innovación en Química Avanzada (ORFEO-CINQA)CSIC and Universidad de SevillaAvda. Américo Vespucio 4941092SevillaSpain
| | - Salvador Conejero
- Instituto de Investigaciones Químicas (IIQ)Departamento de Química InorgánicaCentro de Innovación en Química Avanzada (ORFEO-CINQA)CSIC and Universidad de SevillaAvda. Américo Vespucio 4941092SevillaSpain
| | - Israel Fernández
- Departamento de Química OrgánicaCentro de Innovación en Química Avanzada (ORFEO-CINQA)Facultad de Ciencias QuímicasUniversidad Complutense de MadridCuidad Universitaria28040-MadridSpain
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22
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Mizerska U, Rubinsztajn S, Chojnowski J, Cypryk M, Uznanski P, Walkiewicz-Pietrzykowska A, Fortuniak W. Self-Restructuring of Polyhydromethylsiloxanes by the Hydride Transfer Process: A New Approach to the Cross-Linking of Polysiloxanes and to the Fabrication of Thin Polysiloxane Coatings. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6981. [PMID: 36234320 PMCID: PMC9570814 DOI: 10.3390/ma15196981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The branching and cross-linking of siloxane polymers are important processes in silicone technology. A new type of such a process has been developed, which is a self-restructuring of linear polyhydromethylsiloxane (PHMS). This process involves the reorganization of the PHMS to form a highly branched siloxane polymer or finally a cross-linked siloxane network. It occurs through the transfer of a hydride ion between silicon atoms catalyzed by tris(pentafluoromethyl)borane. Its advantage over existing branching and cross-linking reactions is that it runs at room temperature without a low-molecular-weight cross-linker in the absence of water, silanol groups, or other protic compounds and it does not use metal catalysts. The study of this process was carried out in toluene solution. Its course was followed by 1H NMR, 29Si NMR and FTIR, SEC, and gas chromatography. A general mechanism of this new self-restructuring process supported by quantum calculations is proposed. It has been shown that a linear PHMS self-restructured to a highly branched polymer can serve as a pure methylsiloxane film precursor.
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23
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Asymmetric hydrosilylations of N-sulfonyl ketimines and vicinal diimines with chiral boranes. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.154202] [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]
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24
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Zhang C, Liu X, Wang J, Ye Q. A Three-Dimensional Inorganic Analogue of 9,10-Diazido-9,10-Diboraanthracene: A Lewis Superacidic Azido Borane with Reactivity and Stability. Angew Chem Int Ed Engl 2022; 61:e202205506. [PMID: 35713166 PMCID: PMC9541227 DOI: 10.1002/anie.202205506] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Indexed: 12/16/2022]
Abstract
Herein, we report the facile synthesis of a three-dimensional (3D) inorganic analogue of 9,10-diazido-9,10-dihydrodiboraantracene, which turned out to be a monomer in both the solid and solution state, and thermally stable up to 230 °C, representing a rare example of azido borane with boosted Lewis acidity and stability in one. Apart from the classical acid-base and Staudinger reactions, E-H bond activation (E=B, Si, Ge) was investigated. While the reaction with B-H (9-borabicyclo[3.3.1]nonane) led directly to the 1,1-addition on Nα upon N2 elimination, the Si-H (Et3 SiH, PhMe2 SiH) activation proceeded stepwise via 1,2-addition, with the key intermediates 5int and 6int being isolated and characterized. In contrast, the cooperative Ge-H was reversible and stayed at the 1,2-addition step.
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Affiliation(s)
- Chonghe Zhang
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
| | - Xiaocui Liu
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
| | - Junyi Wang
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
- Department of ChemistryThe Hong Kong University of Science and TechnologyClear Water Bay, KowloonHong KongHong Kong
| | - Qing Ye
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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25
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Beck AD, Haufe S, Waldvogel SR. Boron‐catalyzed electrochemical oxidative Si‐C bond formation. ChemElectroChem 2022. [DOI: 10.1002/celc.202200840] [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)
- Alexander D. Beck
- Johannes Gutenberg Universität Mainz: Johannes Gutenberg Universitat Mainz Department Chemie GERMANY
| | - Stefan Haufe
- Wacker Group: Wacker Chemie AG Consortium für Elektrochemie GERMANY
| | - Siegfried R Waldvogel
- Johannes Gutenberg-Universität Mainz Institut für Organische Chemie Duesbergweg 10-14 55128 Mainz GERMANY
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26
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Carmona M, Pérez R, Ferrer J, Rodríguez R, Passarelli V, Lahoz FJ, García-Orduña P, Carmona D. Activation of H-H, HO-H, C(sp 2)-H, C(sp 3)-H, and RO-H Bonds by Transition-Metal Frustrated Lewis Pairs Based on M/N (M = Rh, Ir) Couples. Inorg Chem 2022; 61:13149-13164. [PMID: 35948430 PMCID: PMC9406284 DOI: 10.1021/acs.inorgchem.2c01902] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Reaction of the dimers [(Cp*MCl)2(μ-Cl)2] (Cp* = η5-C5Me5)
with Ph2PCH2CH2NC(NH(p-Tolyl))2 (H2L) in the presence
of NaSbF6 affords the chlorido complexes [Cp*MCl(κ2N,P-H2L)][SbF6] (M = Rh, 1; Ir, 2).
Upon treatment with aqueous NaOH, solutions of 1 and 2 yield the corresponding complexes [Cp*M(κ3N,N′,P-HL)][SbF6] (M = Rh, 3; Ir, 4) in which the ligand HL presents a fac κ3N,N′,P coordination mode. Treatment of THF solutions
of complexes 3 and 4 with hydrogen gas,
at room temperature, results in the formation of the metal hydrido-complexes
[Cp*MH(κ2N,P-H2L)][SbF6] (M = Rh, 5;
Ir, 6) in which the N(p-Tolyl) group
has been protonated. Complexes 3 and 4 react
with deuterated water in a reversible fashion resulting in the gradual
deuteration of the Cp* group. Heating at 383 K THF/H2O
solutions of the complexes 3 and 4 affords
the orthometalated complexes [Cp*M(κ3C,N,P-H2L-H)][SbF6] [M = Rh, 7; Ir, 8, H2L-H = Ph2PCH2CH2NC(NH(p-Tolyl))(NH(4-C6H3Me))], respectively. At 333 K, complexes 3 and 4 react in THF with methanol, primary alcohols,
or 2-propanol giving the metal-hydrido complexes 5 and 6, respectively. The reaction involves the acceptorless dehydrogenation
of the alcohols at a relatively low temperature, without the assistance
of an external base. The new complexes have been characterized by
the usual analytical and spectroscopic methods including the X-ray
diffraction determination of the crystal structures of complexes 1–5, 7, and 8. Notably, the chlorido complexes 1 and 2 crystallize both as enantiopure conglomerates and as racemates.
Reaction mechanisms are proposed based on stoichiometric reactions,
nuclear magnetic resonance studies, and X-ray crystallography as well
as density functional theory calculations. In solution, masked transition-metal
frustrated Lewis pairs
(TMFLPs) give rise to the corresponding TMFLP species which activate
dihydrogen, water, and alcohols following FLP reaction pathways. When
D2O or alcohols with deuterated OH groups were employed,
H/D exchange at the Cp* ligand (involving C(sp3)−H
activation) was observed. C(sp2)−H bond activation
involving orthometalation of the p-Tolyl ring was
also observed.
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Affiliation(s)
- María Carmona
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Roberto Pérez
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Joaquina Ferrer
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Ricardo Rodríguez
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Vincenzo Passarelli
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Fernando J Lahoz
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Pilar García-Orduña
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Daniel Carmona
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
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27
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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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28
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Ríos P, Rodríguez A, Conejero S. Activation of Si-H and B-H bonds by Lewis acidic transition metals and p-block elements: same, but different. Chem Sci 2022; 13:7392-7418. [PMID: 35872827 PMCID: PMC9241980 DOI: 10.1039/d2sc02324e] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 05/18/2022] [Indexed: 01/01/2023] Open
Abstract
In this Perspective we discuss the ability of transition metal complexes to activate and cleave the Si-H and B-H bonds of hydrosilanes and hydroboranes (tri- and tetra-coordinated) in an electrophilic manner, avoiding the need for the metal centre to undergo two-electron processes (oxidative addition/reductive elimination). A formal polarization of E-H bonds (E = Si, B) upon their coordination to the metal centre to form σ-EH complexes (with coordination modes η1 or η2) favors this type of bond activation that can lead to reactivities involving the formation of transient silylium and borenium/boronium cations similar to those proposed in silylation and borylation processes catalysed by boron and aluminium Lewis acids. We compare the reactivity of transition metal complexes and boron/aluminium Lewis acids through a series of catalytic reactions in which pieces of evidence suggest mechanisms involving electrophilic reaction pathways.
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Affiliation(s)
- Pablo Ríos
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica CSIC and Universidad de Sevilla, Centro de Innovación en Química Avanzada (ORFEO-CINQA) C/Américo Vespucio 49 41092 Sevilla Spain
| | - Amor Rodríguez
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica CSIC and Universidad de Sevilla, Centro de Innovación en Química Avanzada (ORFEO-CINQA) C/Américo Vespucio 49 41092 Sevilla Spain
| | - Salvador Conejero
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica CSIC and Universidad de Sevilla, Centro de Innovación en Química Avanzada (ORFEO-CINQA) C/Américo Vespucio 49 41092 Sevilla Spain
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29
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Zhang C, Liu X, Wang J, Ye Q. A Three‐Dimensional Inorganic Analogue of 9,10‐Diazido‐9,10‐Diboraanthracene – A Lewis Superacidic Azido Borane with Reactivity and Stability. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205506] [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)
- Chonghe Zhang
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Xiaocui Liu
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Junyi Wang
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Qing Ye
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Institut für Anorganische Chemie Am Hubland 97074 Würzburg GERMANY
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30
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Singh K, Avigdori I, Kaushansky A, Fridman N, Toledano D, Gandelman M. New Generation of Nitrenium Salts: Catalytic Hydrosilylation of Imines and a Mechanism of Action of Nitrogen Lewis Acids. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01297] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Kuldeep Singh
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Idan Avigdori
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Alexander Kaushansky
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Dor Toledano
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
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31
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Martin JL, Sati GC, Malakar T, Hatt J, Zimmerman PM, Montgomery J. Glycosyl Exchange of Unactivated Glycosidic Bonds: Suppressing or Embracing Side Reactivity in Catalytic Glycosylations. J Org Chem 2022; 87:5817-5826. [PMID: 35413188 PMCID: PMC9173671 DOI: 10.1021/acs.joc.2c00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While developing boron-catalyzed glycosylations using glycosyl fluoride donors and trialkylsilyl ether acceptors, competing pathways involving productive glycosylation or glycosyl exchange were observed. Experimental and computational mechanistic studies suggest a novel mode of reactivity where a dioxolenium ion is a key intermediate that promotes both pathways through addition to either a silyl ether or to the acetal of an existing glycosidic linkage. Modifications in catalyst structure enable either pathway to be favored, and with this understanding, improved multicomponent iterative couplings and glycosyl exchange processes were demonstrated.
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Affiliation(s)
- Joshua L Martin
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Girish C Sati
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Tanmay Malakar
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Jessica Hatt
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - John Montgomery
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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32
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Zulkifly I, Protchenko A, Fuentes MÁ, Hicks J, Aldridge S. Reactions of a Dimethylxanthene‐Derived Frustrated Lewis Pair with Silanes and Stannanes. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200110] [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)
| | | | | | | | - Simon Aldridge
- University of Oxford Chemistry Inorganic Chemistry LaboratorySouth Parks Road SN77RR Oxford UNITED KINGDOM
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33
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Peng Y, Oestreich M. B(C 6F 5) 3-Catalyzed Reductive Denitrogenation of Benzonitrile Derivatives. Org Lett 2022; 24:2940-2943. [PMID: 35417183 DOI: 10.1021/acs.orglett.2c01003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A B(C6F5)3-catalyzed reductive denitrogenation of aromatic nitriles is reported, achieving the metal-free transformation of a cyano into a methyl group in a single synthetic operation. Tris(phenylsilyl)amine is liberated as the nitrogen-containing byproduct. On the basis of control experiments as well as a nuclear magnetic resonance spectroscopic analysis, an SN1-type mechanism involving a trisilylammonium ion as a key intermediate is proposed.
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Affiliation(s)
- Yi Peng
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
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34
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Jupp AR. Evidence for the encounter complex in frustrated Lewis pair chemistry. Dalton Trans 2022; 51:10681-10689. [PMID: 35412552 DOI: 10.1039/d2dt00655c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Frustrated Lewis Pairs (FLPs) are combinations of bulky Lewis acids and bases that can carry out small-molecule activation and catalysis. Mechanistically, the reaction of the acid, base and substrate involves the collision of three distinct molecules, and so the pre-association of the acid and base to form an encounter complex has been proposed. This article will examine the evidence for the formation of this encounter complex, focusing on the archetypal main-group combinations P(tBu)3/B(C6F5)3 and PMes3/B(C6F5)3 (Mes = mesityl), and includes quantum chemical calculations, molecular dynamics simulations, NMR spectroscopic measurements and neutron scattering. Furthermore, the recent discovery that the associated acid and base can absorb a photon to promote single-electron transfer has enabled the encounter complex to also be studied by UV-Vis spectroscopy, EPR spectroscopy, transient absorption spectroscopy, and resonance Raman spectroscopy. These data all support the notion that the encounter complex is only weakly held together and in low concentration in solution. The insights that these studies provide underpin the exciting transformations that can be promoted by FLPs. Finally, some observations and unanswered questions are provided to prompt further study in this field.
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Affiliation(s)
- Andrew R Jupp
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, UK.
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35
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Zou W, Gao L, Cao J, Li Z, Li G, Wang G, Li S. Mechanistic Insight into Hydroboration of Imines from Combined Computational and Experimental Studies. Chemistry 2022; 28:e202104004. [PMID: 35018677 DOI: 10.1002/chem.202104004] [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: 11/06/2021] [Indexed: 12/15/2022]
Abstract
Boron Lewis acid-catalyzed and catalyst-free hydroboration reactions of imines are attractive due to the mild reaction conditions. In this work, the mechanistic details of the hydroboration reactions of two different kinds of imines with pinacolborane (HBpin) are investigated by combining density functional theory calculations and some experimental studies. For the hydroboration reaction of N-(α-methylbenzylidene)aniline catalyzed by tris[3,5-bis(trifluoromethyl)phenyl]borane (BArF 3 ), our calculations show that the reaction proceeds through a boron Lewis acid-promoted hydride transfer mechanism rather than the classical Lewis acid activation mechanism. For the catalyst- and solvent-free hydroboration reaction of imine, N-benzylideneaniline, our calculations and experimental studies indicate that this reaction is difficult to occur under the reaction conditions reported previously. With a combination of computational and experimental studies, we have established that the commercially available BH3 ⋅ SMe2 can serve as an efficient catalyst for the hydroboration reactions of N-benzylideneaniline and similar imines. The hydroboration reactions catalyzed by BH3 ⋅ SMe2 are most likely to proceed through a hydroboration/B-H/B-N σ-bond metathesis pathway, which is very different from that of the reaction catalyzed by BArF 3 .
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Affiliation(s)
- Wentian Zou
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Liuzhou Gao
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Jia Cao
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Zhenxing Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Guoao Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Guoqiang Wang
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Shuhua Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
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36
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Hashikawa Y, Murata Y. Hydrogenation of cage-opened C 60 derivatives mediated by frustrated Lewis pairs. Org Biomol Chem 2022; 20:1000-1003. [PMID: 35029624 DOI: 10.1039/d1ob02316k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multiply-carbonylated fullerene derivatives were found to work as one component in frustrated Lewis pairs which caused an Si-H bond activation in the presence of B(C6F5)3, leading to the carbonyl hydrogenation in up to 99% yield. The Lewis acid-mediated reductive arylation also took place to furnish a corresponding ketal derivative.
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Affiliation(s)
- Yoshifumi Hashikawa
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yasujiro Murata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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37
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Sakata K. Quantum Chemical Studies of Lewis-Acid Catalyzed Organic Chemical Reactions. J SYN ORG CHEM JPN 2022. [DOI: 10.5059/yukigoseikyokaishi.80.115] [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)
- Ken Sakata
- Faculty of Pharmaceutical Sciences, Toho University
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38
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Perutz RN, Sabo‐Etienne S, Weller AS. Metathesis by Partner Interchange in σ-Bond Ligands: Expanding Applications of the σ-CAM Mechanism. Angew Chem Int Ed Engl 2022; 61:e202111462. [PMID: 34694734 PMCID: PMC9299125 DOI: 10.1002/anie.202111462] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Indexed: 12/13/2022]
Abstract
In 2007 two of us defined the σ-Complex Assisted Metathesis mechanism (Perutz and Sabo-Etienne, Angew. Chem. Int. Ed. 2007, 46, 2578-2592), that is, the σ-CAM concept. This new approach to reaction mechanisms brought together metathesis reactions involving the formation of a variety of metal-element bonds through partner-interchange of σ-bond complexes. The key concept that defines a σ-CAM process is a single transition state for metathesis that is connected by two intermediates that are σ-bond complexes while the oxidation state of the metal remains constant in precursor, intermediates and product. This mechanism is appropriate in situations where σ-bond complexes have been isolated or computed as well-defined minima. Unlike several other mechanisms, it does not define the nature of the transition state. In this review, we highlight advances in the characterization and dynamic rearrangements of σ-bond complexes, most notably alkane and zincane complexes, but also different geometries of silane and borane complexes. We set out a selection of catalytic and stoichiometric examples of the σ-CAM mechanism that are supported by strong experimental and/or computational evidence. We then draw on these examples to demonstrate that the scope of the σ-CAM mechanism has expanded to classes of reaction not envisaged in 2007 (additional σ-bond ligands, agostic complexes, sp2 -carbon, surfaces). Finally, we provide a critical comparison to alternative mechanisms for metathesis of metal-element bonds.
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Affiliation(s)
| | - Sylviane Sabo‐Etienne
- CNRSLCC (Laboratoire de Chimie de Coordination)205 route de Narbonne, BP 44099F-31077Toulouse Cedex 4France
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39
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Perutz RN, Sabo‐Etienne S, Weller AS. Metathesis by Partner Interchange in σ‐Bond Ligands: Expanding Applications of the σ‐CAM Mechanism. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202111462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
| | - Sylviane Sabo‐Etienne
- CNRS LCC (Laboratoire de Chimie de Coordination) 205 route de Narbonne, BP 44099 F-31077 Toulouse Cedex 4 France
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40
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Bai D, Wu F, Chang L, Wang M, Wu H, Chang J. Highly Regio‐ and Enantioselective Hydrosilylation of
gem
‐Difluoroalkenes by Nickel Catalysis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202114918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Dachang Bai
- NMPA Key Laboratory for Research and Evaluation of Innovative Drug Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University Xinxiang 453007 China
- State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 P.R. China
| | - Fen Wu
- NMPA Key Laboratory for Research and Evaluation of Innovative Drug Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University Xinxiang 453007 China
| | - Lingna Chang
- NMPA Key Laboratory for Research and Evaluation of Innovative Drug Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University Xinxiang 453007 China
| | - Manman Wang
- NMPA Key Laboratory for Research and Evaluation of Innovative Drug Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University Xinxiang 453007 China
| | - Hao Wu
- NMPA Key Laboratory for Research and Evaluation of Innovative Drug Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University Xinxiang 453007 China
| | - Junbiao Chang
- NMPA Key Laboratory for Research and Evaluation of Innovative Drug Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University Xinxiang 453007 China
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41
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Barthélemy A, Glootz K, Scherer H, Hanske A, Krossing I. Ga +-catalyzed hydrosilylation? About the surprising system Ga +/HSiR 3/olefin, proof of oxidation with subvalent Ga + and silylium catalysis with perfluoroalkoxyaluminate anions. Chem Sci 2022; 13:439-453. [PMID: 35126976 PMCID: PMC8729802 DOI: 10.1039/d1sc05331k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/21/2021] [Indexed: 12/19/2022] Open
Abstract
Already 1 mol% of subvalent [Ga(PhF)2]+[pf]- ([pf]- = [Al(ORF)4]-, RF = C(CF3)3) initiates the hydrosilylation of olefinic double bonds under mild conditions. Reactions with HSiMe3 and HSiEt3 as substrates efficiently yield anti-Markovnikov and anti-addition products, while bulkier substrates such as HSiiPr3 are less reactive. Investigating the underlying mechanism by gas chromatography and STEM analysis, we unexpectedly found that H2 and metallic Ga0 formed. Without the addition of olefins, the formation of R3Si-F-Al(ORF)3 (R = alkyl), a typical degradation product of the [pf]- anion in the presence of a small silylium ion, was observed. Electrochemical analysis revealed a surprisingly high oxidation potential of univalent [Ga(PhF)2]+[pf]- in weakly coordinating, but polar ortho-difluorobenzene of E 1/2(Ga+/Ga0; oDFB) = +0.26-0.37 V vs. Fc+/Fc (depending on the scan rate). Apparently, subvalent Ga+, mainly known as a reductant, initially oxidizes the silane and generates a highly electrophilic, silane-supported, silylium ion representing the actual catalyst. Consequently, the [Ga(PhF)2]+[pf]-/HSiEt3 system also hydrodefluorinates C(sp3)-F bonds in 1-fluoroadamantane, 1-fluorobutane and PhCF3 at room temperature. In addition, both catalytic reactions may be initiated using only 0.2 mol% of [Ph3C]+[pf]- as a silylium ion-generating initiator. These results indicate that silylium ion catalysis is possible with the straightforward accessible weakly coordinating [pf]- anion. Apparently, the kinetics of hydrosilylation and hydrodefluorination are faster than that of anion degradation under ambient conditions. These findings open up new windows for main group catalysis.
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Affiliation(s)
- Antoine Barthélemy
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Kim Glootz
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Harald Scherer
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Annaleah Hanske
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
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42
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Guerzoni MG, van Ingen Y, Melen RL. Recent applications of fluorinated arylborane derivatives. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2022. [DOI: 10.1016/bs.adomc.2022.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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43
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Li Z, Zhang H, Tan T, Lei M. The mechanism of direct reductive amination of aldehyde and amine with formic acid catalyzed by boron trifluoride complexes: insights from a DFT study. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00967f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A volcano diagram of BF3 catalytic species and their activities was proposed for the DRA of aldehyde and amine with formic acid.
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Affiliation(s)
- Zhewei Li
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Institute of Computational Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Huili Zhang
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Institute of Computational Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Tianwei Tan
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Ming Lei
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Institute of Computational Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
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44
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Henkelmann M, Omlor A, Bolte M, Schünemann V, Lerner HW, Noga J, Hrobárik P, Wagner M. A free boratriptycene-type Lewis superacid. Chem Sci 2022; 13:1608-1617. [PMID: 35282635 PMCID: PMC8826627 DOI: 10.1039/d1sc06404e] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/05/2021] [Indexed: 11/21/2022] Open
Abstract
An exceptionally strong ferrocene-containing, cationic boratriptycene-type Lewis acid is stabilized by a weak Fe⋯B through-space interaction.
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Affiliation(s)
- Marcel Henkelmann
- Institute of Inorganic Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Andreas Omlor
- Physics Department, University Kaiserslautern, Erwin-Schrödinger-Straße 56, 67663 Kaiserslautern, Germany
| | - Michael Bolte
- Institute of Inorganic Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Volker Schünemann
- Physics Department, University Kaiserslautern, Erwin-Schrödinger-Straße 56, 67663 Kaiserslautern, Germany
| | - Hans-Wolfram Lerner
- Institute of Inorganic Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Jozef Noga
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 84215 Bratislava, Slovakia
| | - Peter Hrobárik
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 84215 Bratislava, Slovakia
| | - Matthias Wagner
- Institute of Inorganic Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
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45
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Affiliation(s)
- Xiangqing Feng
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Wei Meng
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Haifeng Du
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
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46
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Bai D, Wu F, Chang L, Wang M, Wu H, Chang J. Highly Regio- and Enantioselective Hydrosilylation of gem-Difluoroalkenes via Nickel Catalysis. Angew Chem Int Ed Engl 2021; 61:e202114918. [PMID: 34957676 DOI: 10.1002/anie.202114918] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Indexed: 11/10/2022]
Abstract
The synthesis of small organic molecules with a difluoromethylated stereocenter is particularly attractive in drug discovery. Herein, we developed an efficient method for the direct generation of difluoromethylated stereocenters through Ni(0)-catalyzed regio - and enantioselective hydrosilylation of gem -difluoroalkenes. The reaction also represents the enantioselective construction of carbon(sp 3 )-silicon bonds with nickel catalysis, which provides an atom- and step-economical synthesis route of high-value optically active α-difluoromethylsilanes. This protocol features with readily available starting materials and commercial chiral catalysis, broad substrates spanning a range of functional groups with high yield (up to 99% yield) and excellent enantioselectivity (up to 96% ee). The enantioenriched products undergo a variety of stereospecific transformations. Preliminary mechanistic studies were performed.
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Affiliation(s)
- Dachang Bai
- Henan Normal University, school of chemistry and chemical engineering, 46# jianshe road, 456007, xinxiang, CHINA
| | - Fen Wu
- Henan Normal University, School of Chemistry and Chemical Engineering, CHINA
| | - Lingna Chang
- Henan Normal University, School of Chemistry and Chemical Engineering, CHINA
| | - Manman Wang
- Henan Normal University, School of Chemistry and Chemical Engineering, CHINA
| | - Hao Wu
- Henan Normal University, School of Chemistry and Chemical Engineering, CHINA
| | - Junbiao Chang
- Henan Normal University, School of Chemistry and Chemical Engineering, CHINA
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47
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Gao H, Müller R, Irran E, Klare HFT, Kaupp M, Oestreich M. Competition for Hydride between Silicon and Boron: Synthesis and Characterization of a Hydroborane-Stabilized Silylium Ion. Chemistry 2021; 28:e202104464. [PMID: 34918852 PMCID: PMC9303568 DOI: 10.1002/chem.202104464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Indexed: 11/16/2022]
Abstract
Potent main‐group Lewis acids are capable of activating element‐hydrogen bonds. To probe the rivalry for hydride between silylium‐ and borenium‐ion centers, a neutral precursor with the hydrosilane and hydroborane units in close proximity on a naphthalene‐1,8‐diyl platform was designed. Abstraction of one hydride leads to a hydroborane‐stabilized silylium ion rather than a hydrosilane‐coordinated borenium ion paired with [B(C6F5)4]− or [HCB11Cl11]− as counteranions. Characterization by multinuclear NMR spectroscopy and X‐ray diffraction supported by DFT calculations reveals a cationic, unsymmetrical open three‐center, two‐electron (3c2e) Si−H−B linkage.
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Affiliation(s)
- Haopeng Gao
- Technische Universität Berlin: Technische Universitat Berlin, Chemistry, GERMANY
| | - Robert Müller
- Technische Universität Berlin: Technische Universitat Berlin, Chemistry, GERMANY
| | - Elisabeth Irran
- Technische Universität Berlin: Technische Universitat Berlin, Chemistry, GERMANY
| | - Hendrik F T Klare
- Technische Universität Berlin: Technische Universitat Berlin, Chemistry, GERMANY
| | - Martin Kaupp
- Technische Universität Berlin: Technische Universitat Berlin, Chemistry, GERMANY
| | - Martin Oestreich
- Technische Universität Berlin: Technische Universitat Berlin, Chemistry, Straße des 17. Juni 115, 10623, Berlin, GERMANY
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48
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Chen PH, Hsu CP, Tseng HC, Liu YH, Chiu CW. [Mes- B-TMP] + borinium cation initiated cyanosilylation and catalysed hydrosilylation of ketones and aldehydes. Chem Commun (Camb) 2021; 57:13732-13735. [PMID: 34870288 DOI: 10.1039/d1cc06319g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two aryl amino borinium cations derived from Cl(Mes)B-NR2 (NR2 = TMP, HMDS) faced divergent outcomes. As the HMDS-substituted one underwent methyl migration from silicon to boron transforming the putative borinium ion to a silylium ion, [Mes-B-TMP]+ can initiate cyanosilylation and catalyse hydrosilylation of ketones and aldehydes.
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Affiliation(s)
- Po-Han Chen
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan, Republic of China.
| | - Ching-Pei Hsu
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan, Republic of China.
| | - Hsi-Ching Tseng
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan, Republic of China.
| | - Yi-Hung Liu
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan, Republic of China.
| | - Ching-Wen Chiu
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan, Republic of China.
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49
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Nimoth JP, Müller T. Hydrogen-Bridged Oligosilanylsilyl Mono- and Oligosilanylsilyl Dications. Chemistry 2021; 28:e202104318. [PMID: 34882861 PMCID: PMC9305540 DOI: 10.1002/chem.202104318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Indexed: 11/24/2022]
Abstract
Hydrogen‐bridged oligosilanylsilyl borates 8 [B(C6F5)4], 9[B(C6F5)4] and diborates 10 [B(C6F5)4]2 have been prepared by hydride transfer between α‐ω‐dihydrido‐ (11) and branched tetrahydrido‐oligosilanes (13) and trityl cation. The obtained cyclic intramolecularly stabilized silylium ions 8, 9 and bissilylium ion 10 were characterized by low temperature NMR spectroscopy supported by the results of density functional calculations. The branched Si−H−Si monocation 9 undergoes at low temperatures a fast degenerate rearrangement, which exchanges the Si−H groups with a barrier of 31 kJ mol−1 via an antarafacial transition state. Reaction of the branched monocation 9 with a second equivalent of trityl cation or of the branched oligosilane 13 with two equivalents of trityl cation, gives at −80 °C the corresponding bissilylium ion 10, an example for a new class of highly reactive poly‐Lewis acids.
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Affiliation(s)
- Jelte P Nimoth
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129, Oldenburg, Germany, European Union
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129, Oldenburg, Germany, European Union
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50
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Wang G, Su X, Gao L, Liu X, Li G, Li S. Borane-catalyzed selective dihydrosilylation of terminal alkynes: reaction development and mechanistic insight. Chem Sci 2021; 12:10883-10892. [PMID: 34476068 PMCID: PMC8372554 DOI: 10.1039/d1sc02769g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/13/2021] [Indexed: 12/25/2022] Open
Abstract
Here, we describe simple B(C6F5)3-catalyzed mono- and dihydrosilylation reactions of terminal alkynes by using a silane-tuned chemoselectivity strategy, affording vinylsilanes and unsymmetrical geminal bis(silanes). This strategy is applicable to the dihydrosilylation of both aliphatic and aryl terminal alkynes with different silane combinations. Gram-scale synthesis and conducting the reaction without the exclusion of air and moisture demonstrate the practicality of this methodology. The synthetic utility of the resulting products was further highlighted by the structural diversification of geminal bis(silanes) through transforming the secondary silane into other silyl groups. Comprehensive theoretical calculations combined with kinetical isotope labeling studies have shown that a prominent kinetic differentiation between the hydrosilylation of alkynes and vinylsilane is responsible for the chemoselective construction of unsymmetrical 1,1-bis(silanes). A B(C6F5)3/silane-based system enables the chemoselective dihydrosilylation of terminal alkynes. Using a combination of different types of hydrosilanes, a series of unsymmetrical or symmetrical 1,1-bis(silanes) could be constructed.![]()
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Affiliation(s)
- Guoqiang Wang
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Xiaoshi Su
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Liuzhou Gao
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Xueting Liu
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Guoao Li
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Shuhua Li
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
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