Asymmetric α-amination of aldehydes catalyzed by PS-diphenylprolinol silyl ethers: Remediation of catalyst deactivation for continuous flow operation

Polystyrene (PS)-supported diphenylprolinol silyl ethers have been developed as highly active catalysts for the enantioselective α-amination of aldehydes. Understanding the mechanism of catalyst deactivation has led to the development of reaction conditions notably extending catalyst life in repeated recycling (10 cycles; accumulated TON of 480) and has allowed the implementation of a continuous flow α-amination process (6?min residence time, 8?h operation)..