Salicylate-Directed C-O Bond Cleavage: Iron-Catalyzed Allylic Substitution with Grignard Reagents

摘要

Selective C-O bond cleavage is of high interest for modern organic synthesis. A strategy for selective allylic C-O bond cleavage using ethyl salicylate as a directing leaving group has been developed. The reaction is initiated by the chelation of the ortho-ester phenolic group with iron catalyst. The p-allyl iron intermediate is generated and reacts with Grignard reagents to give the allylic substitution products. The excellent selectivity of C-O bond cleavage is achieved in multiple allylic C-O bondcontaining substrates with the aid of the salicylate-directed strategy.