Synergistic Ni/Co Catalysis in C(sp 2 )-C(sp 3 ) Reductive Coupling: A DFT Study

Abstract

In nickel-catalyzed C(sp 2 )-C(sp 3 ) cross-coupling, employing cost-effective cobalt complexes as co-catalysts presents distinct advantages. The Ni/Co dual-catalyzed reductive coupling of aryl halides and alkyl has emerged as a powerful strategy for forming C(sp 2 )-C(sp 3 ) bonds, yet its detailed mechanistic understanding remains elusive. Herein, we elucidate the mechanism for the reductive coupling between aryl and alkyl electrophiles in the presence of a Ni/Co II (PC) dual catalytic system by density functional theory (DFT). The cobalt catalyst activates alkyl halides via an S N 2 oxidative addition pathway, generating a Co III (Pc)-Alk intermediate, while the nickel catalyst specifically engages aryl halides. The subsequent antialkylation step between these intermediates drives the formation of C(sp 2 )-C(sp 3 ) bonds with high selectivity. These mechanistic insights not only rationalize the enhanced efficiency and high functional-group compatibility of the Ni/Co system but also provide a framework for developing future dual-metal catalytic methodologies. Our findings advance synthetic strategies for constructing complex molecules and highlight the potential of bimetallic catalysis in organic synthesis.