60664-70-2Relevant academic research and scientific papers
Enantioselective Diarylcarbene Insertion into Si-H Bonds Induced by Electronic Properties of the Carbenes
Evans, Declan,Houk, K. N.,Li, Mao-Lin,Li, Wen-Tao,Xu, Bin,Yang, Liang-Liang,Zhou, Qi-Lin,Zhu, Shou-Fei
, p. 12394 - 12399 (2020)
Catalytic enantioselection usually depends on differences in steric interactions between prochiral substrates and a chiral catalyst. We have discovered a carbene Si-H insertion in which the enantioselectivity depends primarily on the electronic characteristics of the carbene substrate, and the log(er) values are linearly related to Hammett parameters. A new class of chiral tetraphosphate dirhodium catalysts was developed; it shows excellent activity and enantioselectivity for the insertion of diarylcarbenes into the Si-H bond of silanes. Computational and mechanistic studies show how the electronic differences between the two aryls of the carbene lead to differences in energies of the diastereomeric transition states. This study provides a new strategy for asymmetric catalysis exploiting the electronic properties of the substrates.
Copper-Mediated Cross-Coupling of Diazo Compounds with Sulfinates
Wang, Qian,Liu, An,Wang, Yan,Ni, Chuanfa,Hu, Jinbo
supporting information, p. 6919 - 6924 (2021/09/11)
A copper-mediated cross-coupling reaction between a diazo compound and a sodium alkane(arene)sulfinate gives a sulfone as the product. This reaction proceeds under mild conditions and features excellent functional group compatibility. A wide range of sodium alkane(arene)sulfinates were successfully applied in this chemistry. Mechanistic studies revealed that the overall reaction efficiency of the sulfinates was in line with their nucleophilicity in this reaction.
Dehalogenative Cross-Coupling of gem-Difluoroalkenes with Alkyl Halides via a Silyl Radical-Mediated Process
Tian, Hao,Yang, Shaoxiang,Wang, Xiaochen,Xu, Wentao,Liu, Yuxiu,Li, Yongqiang,Wang, Qingmin
supporting information, p. 12772 - 12782 (2021/09/13)
Herein, we describe a convenient general protocol for monofluoroalkenylation reactions of alkyl bromides involving cooperative visible-light photoredox catalysis and halogen abstraction. Mechanistic experiments showed that the products were generated by selective cross-coupling of aliphatic radicals with fluoroalkenyl radicals. Silyl radical-mediated halogen abstraction enabled the protocol to be used for the monofluoroalkenylation of a broad range of alkyl and heteroaryl halides. The protocol could be carried out on a gram scale and was applied to cholesterol, indicating its utility for late-stage monofluoroalkenylation reactions.
Direct α-Monofluoroalkenylation of Heteroatomic Alkanes via a Combination of Photoredox Catalysis and Hydrogen-Atom-Transfer Catalysis
Tian, Hao,Xia, Qing,Wang, Qiang,Dong, Jianyang,Liu, Yuxiu,Wang, Qingmin
supporting information, p. 4585 - 4589 (2019/06/17)
In this study, a new C(sp3)-H monofluoroalkenylation reaction involving cooperative visible-light photoredox catalysis and hydrogen-atom-transfer catalysis to afford products generated by selective hydrogen abstraction and radical-radical cross-coupling was described. This mild, efficient reaction shows high regioselectivity for the α-carbon atoms of amines, ethers, and thioethers and thus allows the preparation of monofluoroalkenes bearing various substituents. The reaction was applied to two bioactive molecules, indicating its utility for late-stage monofluoroalkenylation of compounds with inert C(sp3)-H bonds.
Trifluoromethylation and Monofluoroalkenylation of Alkenes through Radical–Radical Cross-Coupling
Wang, Qiang,Qu, Yi,Tian, Hao,Liu, Yuxiu,Song, Hongjian,Wang, Qingmin
supporting information, p. 8686 - 8690 (2019/06/17)
The first visible-light-induced trifluoromethylation and monofluoroalkenylation of simple alkenes via a challenging radical–radical cross-coupling step was achieved. This method provided a mild, step-economical and redox-neutral route to privileged two different fluorinated difunctionalized allyl compounds. The utility of this method is illustrated by late-stage modification of medically important molecules.
