51
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Liu X, Lin EE, Chen G, Li JL, Liu P, Wang H. Radical Hydroboration and Hydrosilylation of gem-Difluoroalkenes: Synthesis of α-Difluorinated Alkylborons and Alkylsilanes. Org Lett 2019; 21:8454-8458. [PMID: 31600080 DOI: 10.1021/acs.orglett.9b03218] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A first example of radical hydroboration and hydrosilylation of gem-difluoroalkenes using ABIN as the radical initiator is described. This protocol features good functional group tolerance, operational simplicity, high atom economy, and easy scale-up, enabling efficient assembly of a wide range of α-difluorinated alkylborons and alkylsilanes in moderate to excellent yields. The synthetic utility of these products is demonstrated by further transformation of the C-B bond and C-Si bond into valuable CF2-containing molecules.
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Affiliation(s)
- Xiaozu Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy , Zunyi Medical University , Zunyi 563006 , P.R. China
| | - E Emily Lin
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , P.R. China
| | - Guojun Chen
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy , Zunyi Medical University , Zunyi 563006 , P.R. China
| | - Ji-Lin Li
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , P.R. China
| | - Peijun Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy , Zunyi Medical University , Zunyi 563006 , P.R. China
| | - Honggen Wang
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , P.R. China
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52
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Jin JK, Zheng WX, Xia HM, Zhang FL, Wang YF. Regioselective Radical Hydroboration of gem-Difluoroalkenes: Synthesis of α-Borylated Organofluorines. Org Lett 2019; 21:8414-8418. [PMID: 31596598 DOI: 10.1021/acs.orglett.9b03173] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A regioselective radical hydroboration of gem-difluoroalkenes was developed for the synthesis of α-difluoroalkylborons. The reaction features excellent regioselectivity, broad substrate scope, and good functional group capability. DFT calculations implicated the remarkable α-selectivity was driven from the kinetically and thermodynamically more favorable α-addition step. The resulting α-difluoroalkylborons could be readily converted into NHC-borane-tethered monofluoroalkenes, which demonstrated unique reactivity and applicability in the synthesis of monofluoroalkene derivatives through transformations of the boron unit.
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Affiliation(s)
- Ji-Kang Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Wan-Xin Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Hui-Min Xia
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Feng-Lian Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Yi-Feng Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China.,State Key Laboratory of Elemento-Organic Chemistry , Nankai University , Tianjin 300071 , China
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53
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Friese FW, Studer A. New avenues for C-B bond formation via radical intermediates. Chem Sci 2019; 10:8503-8518. [PMID: 32015798 PMCID: PMC6977546 DOI: 10.1039/c9sc03765a] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/03/2019] [Indexed: 12/26/2022] Open
Abstract
This perspective gives an overview on recent findings in the emerging area of C-radical borylation using diborons as radical trapping reagents. Aryl, vinyl and alkyl boronic esters can be accessed via such an approach under mild conditions. These processes are complementary to established transition metal catalysed cross coupling reactions. Radical borylations can be conducted in the absence of a transition metal but some processes require transition metals as catalysts. It will be shown that various readily available C-radical precursors can be used to run these borylations. For a better understanding of the chemistry, mechanistic discussions are also presented and an outlook on this topic will be provided at the end of the article.
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Affiliation(s)
- Florian W Friese
- Organisch-Chemisches Institut , Westfälische Wilhelms-Universität , Corrensstrasse 40 , 48149 Münster , Germany .
| | - Armido Studer
- Organisch-Chemisches Institut , Westfälische Wilhelms-Universität , Corrensstrasse 40 , 48149 Münster , Germany .
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54
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Huang YS, Wang J, Zheng WX, Zhang FL, Yu YJ, Zheng M, Zhou X, Wang YF. Regioselective radical hydroboration of electron-deficient alkenes: synthesis of α-boryl functionalized molecules. Chem Commun (Camb) 2019; 55:11904-11907. [PMID: 31528910 DOI: 10.1039/c9cc06506g] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A regioselective radical hydroboration of various electron-deficient alkenes is achieved by the employment of an NHC-boryl radical. A range of α-borylated nitriles, trifluoromethyl molecules, phosphonates, sulfones, and gem-diboron compounds have been prepared from readily available starting materials. Further synthetic applications of these products are also demonstrated.
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Affiliation(s)
- Yun-Shuai Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Jie Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Wan-Xin Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Feng-Lian Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - You-Jie Yu
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Min Zheng
- Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Xiaoguo Zhou
- Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Yi-Feng Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
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55
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Yamamoto K, Mohara Y, Mutoh Y, Saito S. Ruthenium-Catalyzed (Z)-Selective Hydroboration of Terminal Alkynes with Naphthalene-1,8-diaminatoborane. J Am Chem Soc 2019; 141:17042-17047. [DOI: 10.1021/jacs.9b06910] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Kensuke Yamamoto
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Yusei Mohara
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Yuichiro Mutoh
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Shinichi Saito
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
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56
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Affiliation(s)
- Tsuyoshi Taniguchi
- Graduate School of Natural Science and Technology; Kanazawa University; Kakuma-machi 920-1192 Kanazawa Japan
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57
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Grams RJ, Fritzemeier RG, Slebodnick C, Santos WL. trans-Hydroboration of Propiolamides: Access to Primary and Secondary (E)-β-Borylacrylamides. Org Lett 2019; 21:6795-6799. [PMID: 31393740 DOI: 10.1021/acs.orglett.9b02408] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. Justin Grams
- Department of Chemistry, Virginia Tech, 900 West Campus Drive, Blacksburg, Virginia 24061, United States
| | - Russell G. Fritzemeier
- Department of Chemistry, Virginia Tech, 900 West Campus Drive, Blacksburg, Virginia 24061, United States
| | - Carla Slebodnick
- Department of Chemistry, Virginia Tech, 900 West Campus Drive, Blacksburg, Virginia 24061, United States
| | - Webster L. Santos
- Department of Chemistry, Virginia Tech, 900 West Campus Drive, Blacksburg, Virginia 24061, United States
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58
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Longobardi LE, Fürstner A. trans
‐Hydroboration of Propargyl Alcohol Derivatives and Related Substrates. Chemistry 2019; 25:10063-10068. [DOI: 10.1002/chem.201902228] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/07/2019] [Indexed: 01/04/2023]
Affiliation(s)
- Lauren E. Longobardi
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim/Ruhr Germany
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59
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Dietz M, Johnson A, Martínez-Martínez A, Weller AS. The [Rh(Xantphos)]+ catalyzed hydroboration of diphenylacetylene using trimethylamine-borane. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2019.03.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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60
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Ren SC, Zhang FL, Xu AQ, Yang Y, Zheng M, Zhou X, Fu Y, Wang YF. Regioselective radical α-borylation of α,β-unsaturated carbonyl compounds for direct synthesis of α-borylcarbonyl molecules. Nat Commun 2019; 10:1934. [PMID: 31036844 PMCID: PMC6488649 DOI: 10.1038/s41467-019-09825-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 04/02/2019] [Indexed: 12/21/2022] Open
Abstract
Organoboron compounds are highly valuable in synthetic chemistry. In particular, α-borylcarbonyl compounds have shown versatile synthetic applications, owing to fruitful chemistries of both the boryl and carbonyl moieties. However, the synthesis of these molecules still remains tedious and time-consuming. Here we report a straightforward and practical route to synthesize α-borylcarbonyl molecules based on a regioselective radical α-borylation of α,β-unsaturated carbonyl compounds. The reaction features unusual α-regioselectivity and high functional-group compatibility. Further synthetic applications of new α-borylated products were also demonstrated. DFT and kinetic studies implicated that the α-regioselectivity of β-aryl-α,β-unsaturated carbonyl compounds was determined by the thermodynamically more favorable radical α-addition step, whereas the formation of α-addition products from β-alkyl-α,β-unsaturated carbonyl compounds was driven by an energetically favored hydrogen atom transfer step. Given that α,β-unsaturated carbonyl compounds can be easily obtained in abundance and variety, this method enjoys great advantages in diverse and economical synthesis of valuable α-borylcarbonyl molecules. α-Borylcarbonyl compounds are versatile synthons in organic synthesis, however their preparation is often tedious. Here, the authors report a regioselective radical α-borylation of α,β-unsaturated carbonyl compounds to afford α-borylcarbonyl molecules with high selectivity and functional group compatibility.
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Affiliation(s)
- Shi-Chao Ren
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China
| | - Feng-Lian Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China
| | - Ai-Qing Xu
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China
| | - Yinuo Yang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China
| | - Min Zheng
- Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China
| | - Xiaoguo Zhou
- Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China.
| | - Yao Fu
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China.
| | - Yi-Feng Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China. .,State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China.
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61
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Vallet AL, Lacôte E. Thiolation of NHC-boranes: influence of the substitution at boron. Org Biomol Chem 2019; 17:4234-4237. [PMID: 30951071 DOI: 10.1039/c9ob00578a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Several N-Heterocyclic Carbene (NHC)-boryl sulfides with B-substituents were prepared. The added steric hindrance leads to much improved selectivities as only the NHC-boryl mono-sulfides were obtained. The B-substituted NHC-boranes are also conducive to more selective S to N NHC-boryl shift, provided that the NHC used is not too sterically demanding.
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Affiliation(s)
- Anne-Laure Vallet
- ICSN-CNRS, Bâtiment 27, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
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62
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Guo A, Han JB, Zhu L, Wei Y, Tang XY. Site-Selective α-Alkoxyl Alkynation of Alkyl Esters Mediated by Boryl Radicals. Org Lett 2019; 21:2927-2931. [PMID: 30924668 DOI: 10.1021/acs.orglett.9b00985] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel method for site-selective C-H functionalization of ethyl acetate mediated by pyridine-boryl radicals is presented, delivering a variety of 4-phenylbut-3-yn-2-yl acetate derivatives under mild conditions. A distinguishing feature of this reaction is that the pyridine-ligated boryl radicals can abstract the inactive α-hydrogen of the alkoxyl group instead of the α-hydrogen of carbonyl groups described in a previous report using amine-ligated boryl radicals. Significantly, substrates with halogen atoms are compatible under the reaction conditions.
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Affiliation(s)
- Ao Guo
- School of Chemistry and Chemical Engineering and Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica , Huazhong University of Science and Technology , 1037 Luoyu Road , Wuhan 430074 , People's Republic of China
| | - Jia-Bin Han
- School of Chemistry and Chemical Engineering and Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica , Huazhong University of Science and Technology , 1037 Luoyu Road , Wuhan 430074 , People's Republic of China
| | - Lei Zhu
- College of Chemistry and Materials Science , Hubei Engineering University , Hubei 432000 , People's Republic of China
| | - Yin Wei
- State Key Laboratory of Organometallic Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , China
| | - Xiang-Ying Tang
- School of Chemistry and Chemical Engineering and Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica , Huazhong University of Science and Technology , 1037 Luoyu Road , Wuhan 430074 , People's Republic of China
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63
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Shimoi M, Maeda K, Geib SJ, Curran DP, Taniguchi T. Esters as Radical Acceptors: β‐NHC‐Borylalkenyl Radicals Induce Lactonization by C−C Bond Formation/Cleavage on Esters. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Masaki Shimoi
- Graduate School of Natural Science and Technology Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
| | - Katsuhiro Maeda
- Graduate School of Natural Science and Technology Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
- Nano Life Science Institute (WPI-NanoLSI) Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
| | - Steven J. Geib
- Department of Chemistry University of Pittsburgh Pittsburgh PA 15260 USA
| | - Dennis P. Curran
- Department of Chemistry University of Pittsburgh Pittsburgh PA 15260 USA
| | - Tsuyoshi Taniguchi
- Graduate School of Natural Science and Technology Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
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64
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Shimoi M, Maeda K, Geib SJ, Curran DP, Taniguchi T. Esters as Radical Acceptors: β‐NHC‐Borylalkenyl Radicals Induce Lactonization by C−C Bond Formation/Cleavage on Esters. Angew Chem Int Ed Engl 2019; 58:6357-6361. [DOI: 10.1002/anie.201902001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Indexed: 01/22/2023]
Affiliation(s)
- Masaki Shimoi
- Graduate School of Natural Science and Technology Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
| | - Katsuhiro Maeda
- Graduate School of Natural Science and Technology Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
- Nano Life Science Institute (WPI-NanoLSI) Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
| | - Steven J. Geib
- Department of Chemistry University of Pittsburgh Pittsburgh PA 15260 USA
| | - Dennis P. Curran
- Department of Chemistry University of Pittsburgh Pittsburgh PA 15260 USA
| | - Tsuyoshi Taniguchi
- Graduate School of Natural Science and Technology Kanazawa University, Kakuma-machi Kanazawa 920-1192 Japan
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65
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Dai W, Curran DP, Walton JC. EPR and Preparative Studies of 5- endo Cyclizations of Radicals Derived from Alkenyl NHC-Boranes Bearing tert-Butyl Ester Substituents. J Org Chem 2019; 84:2102-2111. [PMID: 30663305 DOI: 10.1021/acs.joc.8b03112] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Radical H atom abstraction from a set of N-heterocyclic carbene (NHC) complexes of alkenylboranes bearing two tert-butyl ester substituents was studied by EPR spectroscopy. The initial boraallyl radical intermediates rapidly ring closed onto the O atoms of their distal ester groups in 5- endo mode to yield 1,2-oxaborole radicals. Unexpectedly, two structural varieties of these radicals were identified from their EPR spectra. These proved to be two stable rotamers, in which the carbonyl group of the tert-butyl ester was oriented toward and away from the NHC ring. These rotamers were akin to the s- trans and s- cis rotamers of α,β-unsaturated carbonyl compounds. Their stability was attributed to the quasi-allylic interaction of their unpaired electrons with the carbonyl units of their adjacent ester groups. EPR spectroscopic evidence for two rotamers of the analogous methyl ester containing NHC-oxaborole radicals was also obtained. An improved synthetic procedure for preparing rare NHC-boralactones was developed involving treatment of the alkenyl NHC-boranes with AIBN and tert-dodecanethiol.
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Affiliation(s)
- Wen Dai
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Dennis P Curran
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - John C Walton
- EaStCHEM School of Chemistry , University of St. Andrews , St. Andrews , Fife KY16 9ST , United Kingdom
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66
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Zhang G, Li S, Wu J, Zeng H, Mo Z, Davis K, Zheng S. Highly efficient and selective hydroboration of terminal and internal alkynes catalysed by a cobalt(ii) coordination polymer. Org Chem Front 2019. [DOI: 10.1039/c9qo00834a] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Selective hydroboration of terminal and internal alkynes is catalysed using a CoII-coordination polymer precatalyst with TOFs of up to 47 520 h−1.
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Affiliation(s)
- Guoqi Zhang
- Department of Sciences
- John Jay College and Ph.D. Program in Chemistry
- The Graduate Center of the City University of New York
- New York
- USA
| | - Sihan Li
- Department of Sciences
- John Jay College and Ph.D. Program in Chemistry
- The Graduate Center of the City University of New York
- New York
- USA
| | - Jing Wu
- Department of Sciences
- John Jay College and Ph.D. Program in Chemistry
- The Graduate Center of the City University of New York
- New York
- USA
| | - Haisu Zeng
- Department of Sciences
- John Jay College and Ph.D. Program in Chemistry
- The Graduate Center of the City University of New York
- New York
- USA
| | - Zixuan Mo
- Department of Sciences
- John Jay College and Ph.D. Program in Chemistry
- The Graduate Center of the City University of New York
- New York
- USA
| | - Keziah Davis
- Department of Sciences
- John Jay College and Ph.D. Program in Chemistry
- The Graduate Center of the City University of New York
- New York
- USA
| | - Shengping Zheng
- Department of Chemistry
- Hunter College
- the City University of New York
- New York
- USA
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67
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de la Vega-Hernández K, Romain E, Coffinet A, Bijouard K, Gontard G, Chemla F, Ferreira F, Jackowski O, Perez-Luna A. Radical Germylzincation of α-Heteroatom-Substituted Alkynes. J Am Chem Soc 2018; 140:17632-17642. [DOI: 10.1021/jacs.8b09851] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Elise Romain
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
| | - Anais Coffinet
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
| | - Kajetan Bijouard
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
| | - Geoffrey Gontard
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
| | - Fabrice Chemla
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
| | - Franck Ferreira
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
| | - Olivier Jackowski
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
| | - Alejandro Perez-Luna
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, F-75005 Paris, France
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68
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Radcliffe JE, Fasano V, Adams RW, You P, Ingleson MJ. Reductive α-borylation of α,β-unsaturated esters using NHC-BH 3 activated by I 2 as a metal-free route to α-boryl esters. Chem Sci 2018; 10:1434-1441. [PMID: 30809360 PMCID: PMC6354834 DOI: 10.1039/c8sc04305a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 11/17/2018] [Indexed: 11/21/2022] Open
Abstract
Useful α-boryl esters can be synthesized in one step from α,β-unsaturated esters using just a simple to access NHC-BH3 (NHC = N-heterocyclic carbene) and catalytic I2. The scope of this reductive α-borylation methodology is excellent and includes a range of alkyl, aryl substituted and cyclic and acyclic α,β-unsaturated esters. Mechanistic studies involving reductive borylation of a cyclic α,β-unsaturated ester with NHC-BD3/I2 indicated that concerted hydroboration of the alkene moiety in the α,β-unsaturated ester proceeds instead of a stepwise process involving initial 1,4-hydroboration; this is in contrast to the recently reported reductive α-silylation. The BH2(NHC) unit can be transformed into electrophilic BX2(NHC) moieties (X = halide) and the ester moiety can be reduced to the alcohol with the borane unit remaining intact to form β-boryl alcohols. The use of a chiral auxiliary, 8-phenylmenthyl ester, also enables effective stereo-control of the newly formed C-B bond. Combined two step ester reduction/borane oxidation forms diols, including excellent e.e. (97%) for the formation of S-3-phenylpropane-1,2-diol. This work represents a simple transition metal free route to form bench stable α-boryl esters from inexpensive starting materials.
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Affiliation(s)
- James E Radcliffe
- School of Chemistry , University of Manchester , Manchester , M13 9PL , UK .
| | - Valerio Fasano
- School of Chemistry , University of Manchester , Manchester , M13 9PL , UK .
| | - Ralph W Adams
- School of Chemistry , University of Manchester , Manchester , M13 9PL , UK .
| | - Peiran You
- School of Chemistry , University of Manchester , Manchester , M13 9PL , UK .
| | - Michael J Ingleson
- School of Chemistry , University of Manchester , Manchester , M13 9PL , UK .
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69
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Jin JK, Zhang FL, Zhao Q, Lu JA, Wang YF. Synthesis of Diverse Boron-Handled N-Heterocycles via Radical Borylative Cyclization of N-Allylcyanamides. Org Lett 2018; 20:7558-7562. [PMID: 30427202 DOI: 10.1021/acs.orglett.8b03303] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A synthetic method based on radical borylation/cyclization cascades of N-allylcyanamides was developed to construct diverse boron-substituted N-heterocycles. In the reaction process, the N-heterocyclic carbene-boryl radical underwent a chemo- and regioselective addition to the alkene moiety, followed by cyclization with the N-cyano group. The resulting amide-iminyl radical intermediates underwent further reactions to afford various boron-tethered N-heterocyclic molecules. Further transformations to access synthetically useful building blocks were also demonstrated.
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Affiliation(s)
- Ji-Kang Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
| | - Feng-Lian Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
| | - Qiang Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
| | - Jun-An Lu
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
| | - Yi-Feng Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Center for Excellence in Molecular Synthesis of CAS, and Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China.,State Key Laboratory of Elemento-Organic Chemistry , Nankai University , Tianjin 300071 , China
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70
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Fürstner A. trans-Hydrogenation, gem-Hydrogenation, and trans-Hydrometalation of Alkynes: An Interim Report on an Unorthodox Reactivity Paradigm. J Am Chem Soc 2018; 141:11-24. [DOI: 10.1021/jacs.8b09782] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
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