Electricity-driven asymmetric Lewis acid catalysis

Catalytic asymmetric electrosynthesis combines the unique features of an electrochemical addition or removal of electrons with the catalytic asymmetric synthesis of enantioenriched molecules. However, identifying suitable catalysts that are compatible with electrochemical conditions and provide a high stereocontrol is a formidable challenge. Here we introduce a versatile electricity-driven chiral Lewis acid catalysis for the oxidative cross-coupling of 2-acyl imidazoles with silyl enol ethers. Powered by an electric current, this work provides a sustainable avenue to synthetically useful non-racemic 1,4-dicarbonyls, which include products that bear all-carbon quaternary stereocentres. A chiral-at-metal rhodium catalyst activates a substrate towards anodic oxidation by raising the highest occupied molecular orbital on enolate formation, which enables mild redox conditions, high chemo- and enantioselectivities (up to >99% enantiomeric excess) and a broad substrate scope. This work demonstrates the potential of combining asymmetric Lewis acid catalysis with electrochemistry and we anticipate that it will spur the further development of catalytic asymmetric electrosynthesis.