Modular synthesis of congested β-amino acids the merger of photocatalysis and oxidative functionalisations.

A two-step protocol for the modular synthesis of β- and α-quaternary β-amino acid derivatives is reported. The key steps are a photocatalytic hydroalkylation reaction, followed by an oxidative functionalisation to access -protected β-amino acids, esters, and amides. This strategy can be effectively scaled up continuous-flow technology.