Iron‐Catalyzed Coupling of Aryl Grignard Reagents with Alkyl Halides: A Competitive Hammett Study

Abstract

Competing for electrophiles: The elusive iron-catalyzed CC coupling reaction was investigated and analyzed by a Hammett study of the nucleophilic partner. This required finding conditions in which the iron catalyst is stable in the presence of an excess of the Grignard reagent. The selectivity-determining step seems to be the transmetalation, occurring either before or after the oxidative addition step (see scheme).