Enantioselective BINOL-phosphoric acid catalyzed Pictet-Spengler reactions of N-benzyltryptamine.
Optically active tetrahydro-beta-carbolines were synthesized via an ( R)-BINOL-phosphoric acid-catalyzed asymmetric Pictet-Spengler reaction of N-benzyltryptamine with a series of aromatic and aliphatic aldehydes. The tetrahydro-beta-carbolines were obtained in yields ranging from 77% to 97% and with ee values up to 87%. The triphenylsilyl-substituted BINOL-phosphoric acid proved to be the catalyst of choice for the reaction with aromatic aldehydes. For the aliphatic aldehydes, 3,5-bistrifluoromethylphenyl-substituted BINOL-phosphoric acid was identified as the best catalyst.
Sewgobind
Nishant V
NV
Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS, Amsterdam, The Netherlands.
Wanner
Martin J
MJ
Ingemann
Steen
S
de Gelder
René
R
van Maarseveen
Jan H
JH
Hiemstra
Henk
H
D000447:Aldehydes / Q000737:chemistry; D001593:Benzyl Compounds / Q000737:chemistry; D002243:Carbolines / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D009284:Naphthols / Q000737:chemistry*; D010084:Oxidation-Reduction; D010756:Phosphoric Acids / Q000737:chemistry*; D013237:Stereoisomerism; D014363:Tryptamines / Q000737:chemistry*
D000447:Aldehydes; C406944:BINOL, naphthol; D001593:Benzyl Compounds; D002243:Carbolines; D009284:Naphthols; D010756:Phosphoric Acids; D014363:Tryptamines