Heterogeneous Dipeptide‐Catalyzed α‐Amination of Aldehydes in a Continuous‐Flow Reactor: Effect of Residence Time on Enantioselectivity

Abstract A solid‐supported dipeptide‐catalyzed continuous‐flow process was developed for the direct enantioselective α‐amination of aldehydes with dibenzyl azodicarboxylate as the electrophilic nitrogen source. With residence time control as an efficient tool for the fine‐tuning of the enantioselectivity, synthetically useful α‐hydrazino alcohols were achieved with excellent ee s. The packed‐bed system proved to be highly robust: no decrease in catalyst activity or selectivity was detected throughout 20 h of continuous‐flow operation. magnified image