The Development and Application of SPSiBox Ligands: Cu-Catalyzed Enantioselective Carbene Insertion of Ge–H Bonds

A class of C2-symmetrical bisoxazoline ligands with a flexible chiral pocket has been developed, which could be readily prepared in three steps from enantiopure SPSiOLs. This type of ligands presented high level of enantioselectivity for the Cu-catalyzed asymmetric carbene insertion of Ge–H bonds with α-trifluoromethyl diazo compounds, thus providing an efficient method for the preparation of enantioenriched α-trifluoromethyl ogranogermanes. This reac-tion features a broad substrates scope, mild reaction conditions, excellent enantioselectivity, and low catalyst loading. Preliminary mechanistic studies un-veiled that this Cu-catalyzed Ge–H insertion might undergo a concerted mechanism, and computational studies unveiled the origin of chiral induction of this reaction with SPSiBox ligand.