季鏻盐支载手性咪唑啉酮不对称催化1,3-偶极环加成反应研究

Asymmetric 1,3-dipolar cycloadditions catalyzed by phosphonium salts supported chiral imidazolidinone

以芳基季鏻盐支载的手性咪唑啉酮为催化剂,不对称催化硝酮偶极子与α,β-不饱和醛的1,3-偶极环加成反应,得到异噁唑醛化合物,并对该反应条件和催化底物进行优化和探究,该反应具有较高的产率（62%-82%）和良好的立体选择性（endo/exo在83/17-94/6之间）,手性催化剂易于回收并可循环使用,且循环4次后的产率不低于60%.

The tetraarylphosphonium supported chiral imidazolidinone catalyzes the stereoselective 1,3-dipolar cycloadditions of nitrones andα,β-unsaturated aldehydes to provide isoxazolidine aldehydes in good yields with good diastereo-and enantioselectivities.what＇s more,the tetraarylphosphonium supported imidazolidinone catalyst could be readily recovered and recycled.