Ugi and Passerini reactions enable the incorporation of Delta AA into N-alkylated peptides and depsipeptides

This work renders operational simplicity under mild conditions to synthesize some N-alkylated peptides and depsipeptides containing olefins. A sequential one-pot protocol merging a multicomponent reaction with oxidative elimination of phenylselenoxide allows the formation of alpha,beta and beta,gamma olefin containing peptides and depsipeptides. Consequently, the regioselective construction of alpha,beta-dehydrobutyrine and alpha,beta-dehydro-homophenylalanine was possible using the Ugi four-component reaction; meanwhile, the Passerini three-component reaction produces the beta-enamide preferably.