ChemInform Abstract: Diphenylprolinol Silyl Ether as a Catalyst in an Enantioselective, Catalytic Michael Reaction for the Formation of α,α‐Disubstituted α‐Amino Acid Derivatives.

Abstract

Oxazole derivatives R 0220Diphenylprolinol Silyl Ether as a Catalyst in an Enantioselective, Catalytic Michael Reaction for the Formation of α,α-Disubstituted α-Amino Acid Derivatives. -Highly enantioselective Michael reaction of α,β-unsaturated aliphatic aldehydes (I) with oxazolidinone derivatives (II) is achieved in the presence of O-Tbs-diphenylprolinol as organocatalyst. Masked quaternary α-amino acid derivatives (III) are obtained in up to 99% e.e. and up to >90% d.e. The analogous reaction of aromatic α,β-unsaturated aldehydes is significantly less diastereoselective. -(HAYASHI*, Y.; OBI, K.; OHTA, Y.; OKAMURA, D.; ISHIKAWA, H.; Chem. Asian J. 4 (2009) 2, 246-249; Dep. Ind. Chem., Fac. Eng., Sci. Univ. Tokyo, Shinjuku, Tokyo 162, Japan; Eng.) -Mischke 22-123