title: 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.
abstract: Trigonoliimines 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 exoimine. 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.
authors.affiliation: Laboratory of Synthesis and Natural Products Institute of Chemical Sciences and Engineering Ecole Polytechnique Fédérale de Lausanne EPFL-SB-ISIC-LSPN, CH-1015 Lausanne, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Buyck
authors.affiliation: Laboratory of Synthesis and Natural Products Institute of Chemical Sciences and Engineering Ecole Polytechnique Fédérale de Lausanne EPFL-SB-ISIC-LSPN, CH-1015 Lausanne, Switzerland.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Laboratory of Synthesis and Natural Products Institute of Chemical Sciences and Engineering Ecole Polytechnique Fédérale de Lausanne EPFL-SB-ISIC-LSPN, CH-1015 Lausanne, Switzerland. jieping.zhu@epfl.ch.
authors.forename: Jieping
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000596:Amino Acids / Q000138:chemical synthesis*; D002384:Catalysis; D061565:Cycloaddition Reaction; D007097:Imines / Q000737:chemistry; D026121:Indole Alkaloids / Q000138:chemical synthesis*; D015394:Molecular Structure; D016566:Organoselenium Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013876:Thiophenes / Q000737:chemistry
chemical_list: D000085:Acetates; D000596:Amino Acids; D007097:Imines; D026121:Indole Alkaloids; D016566:Organoselenium Compounds; D013876:Thiophenes; C551378:trigonoliimine B; C007659:ethyl cyanoacetate; C013693:sulfolane