One-pot reductive coupling of N-acylcarbamates with activated alkenes: application to the asymmetric synthesis of pyrrolo[1,2-a]azepin-5-one ring system and (−)-xenovenine
cyclic N-acylcarbamates can be used as stable substrates, and a range of activated alkenes serve as effective radical receptors. The reductive coupling of l-N-acylcarbamates 12/13 gave 2,5-disubstitutedpyrrolidine derivatives in high trans-diastereoselectivities. The reductive coupling with penta-2,4-dienoate proceeded exclusively in a 1,6-addition fashion, producing a single non-conjugated E-isomer