title: Phase-transfer-catalyzed asymmetric S(N)Ar reaction of α-amino acid derivatives with arene chromium complexes.
abstract: Although phase-transfer-catalyzed asymmetric S(N)Ar reactions provide unique contribution to the catalytic asymmetric α-arylations of carbonyl compounds to produce biologically active α-aryl carbonyl compounds, the electrophiles were limited to arenes bearing strong electron-withdrawing groups, such as a nitro group. To overcome this limitation, we examined the asymmetric S(N)Ar reactions of α-amino acid derivatives with arene chromium complexes derived from fluoroarenes, including those containing electron-donating substituents. The arylation was efficiently promoted by binaphthyl-modified chiral phase-transfer catalysts to give the corresponding α,α-disubstituted α-amino acids containing various aromatic substituents with high enantioselectivities.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan); Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521 (Japan).
authors.forename: Seiji
authors.initials: S
authors.lastname: Shirakawa
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Keiji
authors.initials: K
authors.lastname: Maruoka
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002384:Catalysis; D002857:Chromium / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D056831:Coordination Complexes; D002857:Chromium
keywords: amino acids; arylation; asymmetric synthesis; organocatalysis; phase-transfer catalysis