Palladium-catalyzed expedient Heck annulations in 1-bromo-1,5-dien-3-ols: Exceptional formation of fused bicycles
作者:Jayanta K. Ray、Raju Singha、Devalina Ray、Paramita Ray、Davuluri Yogeswara Rao、Anakuthil Anoop
DOI:10.1016/j.tetlet.2019.02.043
日期:2019.3
Pd-catalyzed intramolecular Heck cyclization has been investigated on halogenated diene scaffolds undergoing various mode of cyclization and termination leading to the formation of structurally differing fused cyclopenta(e)none and aromatic analogue. The discrimination in the fate of palladium intermediates formed in situ undergoing Heck cyclization preferentially arises out of the difference in reaction temperature
在经历各种环化和终止反应导致结构上不同的稠合环戊烯(e)none和芳香族类似物形成的卤化二烯支架上,已经研究了前所未有的Pd催化的分子内Heck环化反应。优先进行Heck环化反应的原位形成的钯中间体的命运之所以有区别,是因为反应温度和底物结构的差异。1-Bromo-5-甲基-1-芳基-hexa-1,5-dien-3-ol衍生物的顺序Heck反应,然后通过sp 2 C氧化或终止芳环中的H活化导致稠合的环戊烷的形成。然而,在升高的温度下,类似的反应显示出主要通过一锅环化和脱羟基化形成芳族类似物的作用。基于密度泛函理论的计算支持了与环丙烷环系统稠合的环戊酮的形成机理。