Regio-, Diastereo- and Enantioselective Hydrosilylation of Alkyl gem-Difluoroalkenes to Construct Carbon and Silicon Stereogenic Centers

Abstract

The asymmetric hydrofunctionalization of aliphatic alkenes without auxiliary or stabilizing groups presents a significant challenge in modern organic synthesis. We report herein the nickel-catalyzed enantioselective hydrosilylation of alkyl-substituted gem-difluoroalkenes, which enables the generation of chiral α-difluoromethylsilanes with excellent regio- and enantioselectivity. Moreover, the simultaneous construction of carbon- and silicon-stereogenic centers was achieved with excellent diastereo- and enantioselectivity using prochiral silanes. This method provides an efficient approach to access sp3-enriched C-stereogenic centers equipped with high-value difluoromethyl groups. The resulting enantioenriched silanes could undergo a range of stereospecific transformations. Density functional theory (DFT) calculations were performed to elucidate the detailed mechanism.

Keywords: Nickel catalysis; alkyl gem-difluoroalkenes; hydrosilylation; silicon stereogenic center; α-difluoromethyl center.