A diastereoselective synthesis of pyrrolo/pyridoisoindole via alkyne iminium ion cyclization of vinylogous carbamate is described. This protocol features a broad substrate scope and easy scalability. An unusual 1,3-alkyl shift is observed with the substrates bearing a strong electron-donating group at the phenyl ring attached to alkyne.
Abstract
An efficient, acid-mediated, intramolecular alkyne iminium ion cyclization of oxoisoindolidene for the diastereoselective synthesis of pyrrolo/pyridoisoindole is described. This protocol features broad substrate scope and easy scalability. An unusual N to C-1,3-alkyl shift is observed with substrates bearing strong electron donating group at the phenyl ring attached to alkyne with concomitant hydration of alkyne to the ketone.