title: 4-(Dimethylamino)pyridine N-oxide (DMAPO): an effective nucleophilic catalyst in the peptide coupling reaction with 2-methyl-6-nitrobenzoic anhydride.
abstract: Various carboxamides or peptides were synthesized from the corresponding carboxylic acids and amines or alpha-amino acids in high yields by the catalysis of 4-(dimethylamino)pyridine N-oxide (DMAPO) with 2-methyl-6-nitrobenzoic anhydride (MNBA). Because the segment-coupling reaction of alpha-amino acids proceeds through the effective activation of the carboxylic acid moieties with DMAPO in the presence of tertiary amines under mild conditions, undesired racemization was hardly observed in the synthesis of oligopeptides such as Z-Gly-Phe-Val-OMe, Z-Phe-Val-Ala-OMe, and Bz-Val-Val-OMe.
authors.affiliation: Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan. shiina@rs.kagu.tus.ac.jp
authors.forename: Isamu
authors.initials: I
authors.lastname: Shiina
authors.forename: Hisaya
authors.initials: H
authors.lastname: Ushiyama
authors.forename: Yo-ko
authors.initials: YK
authors.lastname: Yamada
authors.forename: Yo-ichi
authors.initials: Y
authors.lastname: Kawakita
authors.forename: Kenya
authors.initials: K
authors.lastname: Nakata
mesh_terms: D000812:Anhydrides / Q000737:chemistry*; D002384:Catalysis; D003497:Cyclic N-Oxides / Q000737:chemistry*; D015394:Molecular Structure; D009579:Nitrobenzoates / Q000737:chemistry*; D010087:Oxides / Q000138:chemical synthesis* / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*
chemical_list: C526944:2-methyl-6-nitrobenzoic anhydride; C526943:4-(dimethylamino)pyridine N-oxide; D000812:Anhydrides; D003497:Cyclic N-Oxides; D009579:Nitrobenzoates; D010087:Oxides; D010455:Peptides