Catalytic asymmetric epoxidation of α,β-unsaturated N-acylpyrroles as monodentate and activated ester equivalent acceptors
作者:Shigeki Matsunaga、Hongbo Qin、Mari Sugita、Shigemitsu Okada、Tomofumi Kinoshita、Noriyuki Yamagiwa、Masakatsu Shibasaki
DOI:10.1016/j.tet.2005.12.074
日期:2006.7
Catalytic asymmetric epoxidation of α,β-unsaturated N-acylpyrroles as monodentate and activated ester equivalent acceptors is described. A Sm(O-i-Pr)3/(R)-H8-BINOL complex promoted the epoxidation reaction to afford products in high yield (up to quant) and high enantiomeric excess (up to >99.5% ee). Reaction proceeded smoothly using cumene hydroperoxide (CMHP) with low explosive hazard, and completed
描述了作为单齿和活化酯当量受体的α,β-不饱和N-酰基吡咯的催化不对称环氧化。Sm(O - i -Pr)3 /(R)-H 8 -BINOL配合物促进环氧化反应,从而以高收率(最高定量)和高对映体过量(最高> 99.5%ee)提供产物。使用氢过氧化枯烯(CMHP),爆炸危险低,反应顺利进行,并在0.2-0.5 h内用5 mol%的催化剂完成反应。催化剂载量成功降低至0.02 mol%。还描述了N-酰基吡咯性质以及α,β-不饱和N-酰基吡咯的有效合成。