Cu-Catalyzed Enantioselective Carbene Insertion into Ge–H and Si–H Bonds Enabled by SPSiBox with a Tunable Chiral Pocket

Abstract

Here, we report the Cu-catalyzed asymmetric carbene insertion into both Ge–H and Si–H bonds with α-trifluoromethyl diazo compounds, enabled by a class of newly developed C₂-symmetrical bisoxazoline ligands. This protocol provides an efficient method for the preparation of enantioenriched α-trifluoromethyl ogranogermanes and organosilanes, featuring a broad substrate scope, mild reaction conditions, excellent enantioselectivity, and low catalyst loading. The key to the tolerance of both Si–H and Ge–H bonds is the use of SPSiBox ligands bearing a flexible and tunable chiral pocket. Preliminary mechanistic studies and computational studies unveiled the origin of chiral induction with SPSiBox ligands, the mechanism of Cu-catalyzed Ge–H insertion. This method not only provides a new method for the construction of trifluoromethyl-containing chiral molecules but also opens a new avenue for the preparation of chiral Si- and Ge-containing functional molecules.