Photocyclization of coumarinoyl enamides revisited: [2+2+2] cycloreversion/cycloaddition mechanism
作者:Sivanna Chithanna、Ding-Yah Yang
DOI:10.1039/d1nj00352f
日期:——
The major and minor products for the photocyclization of coumarinoyl enamides were identified. Controlled and intermediate-trapping experiments indicate that the formation of the minor isomer involved a stepwise, radical [2+2+2] cycloreversion/cycloaddition mechanism. Deuterium labeling studies suggest that the photocyclization of both aroyl and alkenoyl enamides involved a [1,5] hydrogen shift as
确定了香豆素酰基酰胺酰胺光环化的主要和次要产品。受控和中间捕获实验表明,次要异构体的形成涉及逐步的,自由基的[2 + 2 + 2]环还原/环加成机理。氘标记研究表明,芳基和链烯基酰胺的光环化都涉及[1,5]氢位移,这是关键步骤,但是不同的氢原子迁移了。