One??Step Catalytic Enantioselective α??Quaternary 5??Hydroxyproline Synthesis: An Asymmetric Entry to Highly Functionalized α??Quaternary Proline Derivatives

P Breistein, J Johansson, I Ibrahem…

Index: Breistein, Palle; Johansson, Jonas; Ibrahem, Ismail; Lin, Shuangzheng; Deiana, Luca; Sun, Junliang; Cordova, Armando Advanced Synthesis and Catalysis, 2012 , vol. 354, # 6 p. 1156 - 1162

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Citation Number: 10

Abstract

Abstract The highly enantioselective cascade reaction between N-protected α-cyanoglycine esters and α, β-unsaturated aldehydes is disclosed. The reaction represents a one-step entry to polysubstituted 5-hydroxyproline derivatives having a quaternary α-stereocenter generally in high yields with up to> 95: 5 dr and 99: 1 er. It is also a direct catalytic two-step entry to functionalized α-quaternary proline derivatives.