Enantioselective copper-catalysed defluorosilylation of trifluoro-methylated alkenes with silylboronates. Issue 18 (12th August 2020)

• Record Type: Journal Article
• Authors: Gao, Pan; Gao, Liuzhou; Xi, Longlong; Zhang, Zedong; Li, Shuhua; Shi, Zhuangzhi
• Is Part Of: Organic chemistry frontiers. Volume 7:Issue 18(2020)
• Page Start: 2618
• Page End: 2627
• Publication Date: 2020-08-12
• Subjects: Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1039/d0qo00773k
• Languages: English
• ISSNs: 2052-4110

Abstract

Abstract : An efficient method for the construction of gem -difluoroallylsilanes with high enantiomeric excess via a copper-catalysed defluorosilylation of trifluoromethylated alkenes with silylboronates is described. Abstract : An efficient method for the construction of gem -difluoroallylsilanes with high enantiomeric excess via a copper-catalysed defluorosilylation of trifluoromethylated alkenes with silylboronates is described. The key to this high enantioselectivity is the careful selection of NaOH as the base and using a triazolium-based chiral N-heterocyclic carbene (NHC) as a ligand in the presence of a copper catalyst. The reaction conditions are mild, and excellent functional group compatibility is observed. This strategy addresses the limitations of the previously described base-mediated defluorosilylation under transition metal-free conditions, which can lead to erosion of the enantioselectivity. The synthetic utilities of the obtained gem -difluoroallylsilanes are also presented. Computational and experimental data suggest that the reaction proceeds through the enantioselective insertion of silyl-Cu/NHC species into the double bond of trifluormethyl alkenes and the Cu-mediated β-F elimination steps.