Sahoo H,
Zhang L,
Cheng J,
Nishiura M,
Hou Z.
*
RIKEN Center for Sustainable Resource Science, Wako, Japan
Auto-Tandem Copper-Catalyzed Carboxylation of Undirected Alkenyl C–H Bonds with CO
2 by Harnessing β‑Hydride Elimination.
J. Am. Chem. Soc. 2022;
144: 23585-23594
DOI:
10.1021/jacs.2c10754
Key words
copper catalysis - borylation - carbonylation - tandem reaction
Significance
Zhang and Hou report the highly selective C–H carboxylation of styrene derivatives
to access α,β-unsaturated esters using copper catalysis. In-depth mechanistic studies
reveal novel catalytic activity and a potential pathway involving two catalytic cycles
linked by an in situ generated copper-alkoxide species (A). Notably, the authors propose CO2 acts as a multitasking carboxylation reagent.
Comment
Compound A enables borylcupration of the alkene to generate intermediate C. The β-H elimination generates vinyl boronate F and a copper hydride species, which instantly reacts with CO2 to form copper formate E. Formation of E enables regeneration of A and initiates the tandem catalytic cycle. Transmetalation of A and F forms the nucleophilic organocopper G. CO2 insertion and metathesis with the alkoxide base regenerates A, while product J is obtained following protolysis and methylation.
