Chiral dihydrobenzo[1,4]oxazines as catalysts for the asymmetric transfer-hydrogenation of α,β-unsaturated aldehydes
作者:Christian Ebner、Andreas Pfaltz
DOI:10.1016/j.tet.2011.10.051
日期:2011.12
A new class of organocatalysts based on the structure of 2,3-dihydrobenzo[1,4]oxazine was prepared and applied in the enantioselective transfer-hydrogenation of α,β-unsaturated aldehydes with Hantzsch ester as hydride donor. These catalysts proved to be particularly effective for the conjugate reduction of β,β-diaryl-substituted acrylaldehydes leading to saturated aldehydes bearing a stereogenic center
制备了一种基于2,3-二氢苯并[1,4]恶嗪结构的新型有机催化剂,并将其用于以Hantzsch酯为氢化物供体的α,β-不饱和醛的对映选择性转移加氢。这些催化剂被证明对于共轭还原β,β-二芳基取代的丙烯醛特别有效,从而导致带有两个立体不同的芳基的立体异构中心的立体醛,对映选择性高达91%ee。