Regio- and Stereospecific <i>C</i>- and <i>O</i>-Allylation of Phenols via π-Allyl Pd Complexes Derived from Allylic Ester Carbonates
作者:Christopher A. Discolo、Alexander G. Graves、Donald R. Deardorff
DOI:10.1021/acs.joc.6b02608
日期:2017.1.20
for the C- and O-allylation of phenols via a common π-allyl Pd complex. While O-allylation of phenols by this method is a well-recognized reaction of general utility, the associated para-selective C-allylation reaction is still in its infancy. Cationic π-allyl Pd intermediates, derived from allylic ester carbonates and palladium(0) catalyst, were found to undergo the Friedel–Crafts-type para-selective
通过共同的π-烯丙基Pd络合物,已开发出两种互补的策略用于苯酚的C-和O-烯丙基化。尽管通过这种方法进行的酚的O-烯丙基化是公认的通用反应,但是相关的对位选择性C-烯丙基化反应仍处于起步阶段。发现衍生自烯丙基碳酸酯和钯(0)催化剂的阳离子π-烯丙基Pd中间体经历了9种不同酚的Friedel-Crafts型对选择性C-烯丙基化反应。这两个C-和O-在金属催化的区域和立体有向取代性1,3-移位后,可以得到高至极好收率的烯丙基化产物。还确定了控制进入任一烯丙基化产品的条件。最后,对两种烯丙基化产物之间建立的平衡的研究表明,O-烯丙基化的化合物是动力学产物,而C-烯丙基化的化合物是热力学产物。