title: Enantioselective addition of ketene silyl acetals to nitrones catalyzed by chiral titanium complexes. Synthesis of optically active beta-amino acids.
abstract: A chiral titanium complex, Ti(O-i-Pr)(4)/BINOL/tert-butylcatechol, catalyzes enantioselective addition reaction of ketene silyl acetals to nitrones to give optically active beta-amino acid derivatives which are biologically active compounds and useful synthetic intermediates of natural products and pharmaceuticals such as beta-lactam antibiotics. The combined process of catalytic oxidation of secondary amines and enantioselective carbon-carbon bond formation of nitrones thus obtained with ketene silyl acetals provides a useful two-step method for the synthesis of optically active beta-amino acid derivatives and related nitrogen compounds.
authors.affiliation: Department of Chemistry, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Shun-Ichi
authors.initials: S
authors.lastname: Murahashi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Imada
authors.forename: Toru
authors.initials: T
authors.lastname: Kawakami
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Harada
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Yonemushi
authors.forename: Naomi
authors.initials: N
authors.lastname: Tomita
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000596:Amino Acids / Q000138:chemical synthesis*; D005030:Ethylenes / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000080:Acetals; D000596:Amino Acids; D005030:Ethylenes; D007659:Ketones; D009589:Nitrogen Oxides; C015388:nitrones; C008223:ketene; D012825:Silicon