Ring Expansion and 1,2‐Migration Cascade of Benzisoxazoles with Ynamides: Experimental and Theoretical Studies
作者:Rajeshwer Vanjari、Shubham Dutta、B. Prabagar、Vincent Gandon、Akhila K. Sahoo
DOI:10.1002/asia.201901251
日期:2019.12.13
α-imino vinylic gold intermediate, and 1,2-migration of the sulfonamide motif to the masked carbene center to deliver the respective ring-expanded benzo[e][1,3]oxazine of predominant E configuration. A trapping experiment justifies the participation of the α-imino masked gold carbene. DFT computations also support the hypothesized mechanism and rationalize the product stereoselectivity.
本文展示了AuI催化的磺酰基保护的酰胺与取代的1,2-苯并恶唑的环合反应,用于合成E-苯并[e] [1,3]恶嗪衍生物。转化涉及将苯异恶唑添加到金活化的酰胺中,苯并异恶唑片段的环扩展以提供α-亚氨基乙烯基金中间体,以及磺酰胺基序的1,2-迁移至被掩盖的卡宾中心以传递相应的环。 E构型的苯并[e] [1,3]恶嗪。诱捕实验证明了α-亚氨基亚胺掩蔽的金卡宾的参与。DFT计算也支持假设的机制并合理化了产物的立体选择性。