reported a novel phosphine-catalyzed (4 + 2) cyclization reaction of electron-deficient conjugated dienes with enones to generate functionalized dihydropyran skeletons. A mechanistic investigation reveals that the reaction produces a new phosphonium zwitterion, which undergoes consecutive reactions. In addition, an asymmetric variant was developed by efficient and economical chiral phosphine catalysis.
在这里,我们报道了一种新型的膦缺乏电子共轭二烯与烯酮的膦催化(4 + 2)环化反应,以生成功能化的二氢
吡喃骨架。机理研究表明,该反应产生新的phospho两性离子,其经历连续反应。另外,通过有效和经济的手性膦催化开发了不对称变体。