Phosphine‐Catalyzed [4+1] Cycloadditions of Allenes with Methyl Ketimines, Enamines, and a Primary Amine
作者:Ze‐Hun Cao、Yu‐Hao Wang、Subarna Jyoti Kalita、Uwe Schneider、Yi‐Yong Huang
DOI:10.1002/anie.201912263
日期:2020.1.27
Unprecedented phosphine-catalyzed [4+1] cycloadditions of allenyl imides have been discovered using various N-based substrates including methyl ketimines, enamines, and a primary amine. These transformations provide a one-pot access to cyclopentenoyl enamines and imines, or (chiral) γ-lactams through two geminal C-C bond or two C-N bond formations, respectively. Several P-based key intermediates including a 1,
使用包括甲基酮亚胺,烯胺和伯胺在内的各种基于N的底物,发现了前所未有的膦催化的烯基酰亚胺的[4 + 1]环加成反应。这些转变分别通过两个双键CC键或两个CN键形成提供了一个一锅通的环戊烯基烯胺和亚胺或(手性)γ-内酰胺的通道。通过31 P NMR和HRMS分析已经检测到了几种基于P的关键中间体,包括1,4-(双)亲电子的α,β-不饱和烯基phospho类,这为假定的催化循环提供了可能。通过克放大催化反应以及区域选择性氢化和双缩合反应分别形成环戊酰基烯胺和稠合的吡唑结构单元,已证明了这种新化学方法的合成用途。