Enantioselective addition of ketene silyl acetals to nitrones catalyzed by chiral titanium complexes. Synthesis of optically active beta-amino acids.
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.
Murahashi
Shun-Ichi
S
Department of Chemistry, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
Imada
Yasushi
Y
Kawakami
Toru
T
Harada
Kazuhito
K
Yonemushi
Yoshiharu
Y
Tomita
Naomi
N
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
D000080:Acetals; D000596:Amino Acids; D005030:Ethylenes; D007659:Ketones; D009589:Nitrogen Oxides; C015388:nitrones; C008223:ketene; D012825:Silicon