An unprecedented organocatalyzed [3 + 2] annulation of cyclopropenones and β-ketoesters has been developed. This reaction provides a direct approach to highly substituted butenolides with a quaternary center in moderate to good yields. The preliminary mechanism study verified that the enol intermediate is crucial to the reaction outcome and the intermolecular esterification and intramolecular Michael
已经开发出前所未有的有机催化的
环戊烯酮和β-酮酸酯的[3 + 2]环。该反应提供了直接的方法,以中等到良好的产率制备具有季中心的高度取代的
丁烯内酯。初步机理研究证实,烯醇中间体对反应结果至关重要,并且涉及分子间酯化和分子内迈克尔加成过程。