From Racemic to Enantioselective Total Synthesis of Trigonoliimines via Development of an Organocatalytic Enantioselective Michael Addition of α-Aryl-α-isocyanoacetate to Vinyl Phenyl Selenone

Buyck, ThomasWang, QianZhu, Jieping2014-05-142014-05-142014-05-14201410.2533/chimia.2014.211https://infoscience.epfl.ch/handle/20.500.14299/103302WOS:000335539100005Trigonoliimines are hexacyclic bisindole alkaloids isolated recently by Hao and co-workers. A synthesis of (±)-trigonoliimine B was accomplished in seven steps from simple starting materials featuring the Bischler-Napieralski reaction for closing the seven-membered ring with concomitant formation of an exo-imine. Sulfolane was found to be the solvent of choice for this unprecedented transformation. An organocatalytic enantioselective synthesis of α,α'-disubstituted α-amino acids was subsequently developed using methyl α-aryl- α-isocyanoacetates as glycine templates and vinyl phenyl selenone as a Michael acceptor. Using one of this Michael adducts as a starting material, total synthesis of both (+)- and (–)-trigonoliimine A was subsequently realized.Asymmetric Michael additionBisindole alkaloidNatural productOrganocatalysisSeleniumTrigonoliiminesFrom Racemic to Enantioselective Total Synthesis of Trigonoliimines via Development of an Organocatalytic Enantioselective Michael Addition of α-Aryl-α-isocyanoacetate to Vinyl Phenyl Selenonetext::journal::journal article::research article