Reaction of Silyldihalomethyllithiums with Nitriles: Formation of α-Keto Acylsilanes via Azirines and 1,3-Rearrangement of Silyl Group from C to N

Abstract
A synthesis of alpha-keto acylsilanes, where 2-bromo-2H-azirine participates as a key intermediate, is reported. The reaction of silyldibromomethyllithium with aryl nitriles provides alpha-keto acylsilanes in good yields. Interestingly, silyldichloromethyllithium induces aza-1,3-Brook rearrangement of the silyl group in th reaction with nitriles. The rearrangement enables a three-component coupling reaction in a one-pot operation.