Iron/Zinc-Co-catalyzed Directed Arylation and Alkenylation of C(sp3)–H Bonds with Organoborates

An iron(III) salt, (Z)-1,2-bis(diphenylphosphino)ethene or its electron-rich congener, (Z)-1,2-bis[bis(4-methoxyphenyl)phosphine]ethene, and a zinc(II) salt catalyze the arylation, heteroarylation, and alkenylation of propionamides possessing an 8-quinolylamide group with organoborate reagents in the presence of 1,2-dichlorobutane as oxidant at 70 °C. Stoichiometric experiments provided evidence for the involvement of an organoiron(III) species as a key intermediate for C–H activation and C–C bond formation.