Polyether Macrocycles from Intramolecular Cyclopropanation and Ylide Formation. Effect of Catalyst and Coordination
作者:Thomas M. Weathers、Yuanhua Wang、Michael P. Doyle
DOI:10.1021/jo0614902
日期:2006.10.1
The use of catalytic metal carbene methodology with diazoacetates for the construction in high yield of polyether macrocycles having ring sizes greater than 25 has been achieved by preventing access to γ-C−H positions for intramolecular insertion. Cyclopropanation is the exclusive outcome of reactions performed with dirhodium(II) catalysts, and product yields of greater than 70% are obtained without
通过防止进入分子内插入的γ-CH位,已经实现了将催化金属卡宾方法与重氮基乙酸盐用于高收率环尺寸大于25的聚醚大环化合物的构建。环丙烷化是用(II)催化剂进行反应的唯一结果,无需使用溶剂进行高稀释即可获得高于70%的产物收率。使用具有多个用于聚醚配位的位点的铜(I)催化剂,在末端氧处形成分子内氧鎓叶立德,随后与环丙烷化竞争,侧链烯丙基的[2,3]-σ重排。钠离子与反应物重氮化合物的配位抑制了铜催化反应中叶立德鎓盐的形成。