Catalyst Choice for Highly Enantioselective [3 + 3]-Cycloaddition of Enoldiazocarbonyl Compounds
作者:Kostiantyn O. Marichev、Frady G. Adly、Alejandra M. Carranco、Estevan C. Garcia、Hadi Arman、Michael P. Doyle
DOI:10.1021/acscatal.8b03391
日期:2018.11.2
Chiral copper(I) catalysts are preferred over chiral dirhodium(II) catalysts for [3 + 3]-cycloaddition reactions of enoldiazocarbonyl compounds with nitrones and acyliminopyridinium ylides, forming chiral oxazines and pyrazines in very high yield and enantioselectivity. Yields and stereoselectivities from reactions of enoldiazoketones are virtually the same as those from the corresponding esters and
手性铜(I)催化剂比手性铜(II)催化剂更优选,因为烯基重氮羰基化合物与硝酮和酰基吡啶并吡啶鎓盐发生[3 + 3]-环加成反应,从而以很高的收率和对映选择性形成手性恶嗪和吡嗪。烯基氮酮的反应的产率和立体选择性与相应的酯和酰胺的产率和立体选择性实际上相同,但是烯基氮酮的产物是手性1,3-二羰基衍生物的前体,它们通过形成吡唑和异恶唑为杂环合成提供了更多机会。