Catalytic Stereoselective Silyl- and Boraformylations: Charting a Challenging Road Ahead

This minireview highlights key milestone discoveries in (stereoselective) silylformylation and boraformylation reactions-formal additions of a formyl group (CHO) and a silyl or boryl group across unsaturated C─C bonds, such as those in alkenes, dienes, alkynes, or allene derivatives. Although these transformations have not yet reached the level of maturity of the parent hydroformylation reaction (the addition of CHO and H across an unsaturated C─C bond), significant progress has nonetheless been achieved. This minireview presents the current state of the art in silylformylation catalysis, emphasizing the chemo- and diastereoselectivities achieved by leading catalytic systems. In contrast, boraformylation remains in its infancy, with only a handful of examples reported in the literature to date. Notably, catalytic enantioselective variants of both silyl- and boraformylation reactions have yet to be realized. This limited progress is primarily attributed to the scarcity of catalysts that effectively combine a metal center with a suitable ligand framework. This minireview article underscores the significant opportunities for advancing catalytic enantioselective methodologies in these areas and the potential for accessing structurally diverse, stereochemically complex molecules through these underdeveloped yet promising transformations.