One-Step Catalytic Enantioselective α-Quaternary 5-Hydroxyproline Synthesis: An Asymmetric Entry to Highly Functionalized α-Quaternary Proline Derivatives
作者:Palle Breistein、Jonas Johansson、Ismail Ibrahem、Shuangzheng Lin、Luca Deiana、Junliang Sun、Armando Cordova
DOI:10.1002/adsc.201100911
日期:2012.4.16
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
公开了在N保护的α-氰基甘氨酸酯和α,β-不饱和醛之间的高度对映选择性级联反应。该反应代表了一步步进入具有季α-立体中心的多取代5-羟基脯氨酸衍生物,通常收率高达95:5 dr和99:1 er。它也是功能化α-季脯氨酸衍生物的直接催化两步进入方法。