Nickel-Catalyzed Atroposelective Carbo-Carboxylation of Alkynes with CO2: En Route to Axially Chiral Carboxylic Acids.

Abstract

Precise synthesis of carboxylic acids via catalytic carboxylation with CO2 is highly appealing. Although considerable advancements have been achieved in difunctionalizing carboxylation of unsaturated hydrocarbons, the asymmetric variants are conspicuously underdeveloped, particularly in addressing axially chiral alkenes. Herein, we report the first catalytic atroposelective carboxylation of alkynes with CO2. A variety of valuable axially chiral carboxylic acids are obtained with good yields and high chemo-, regio-, E/Z and enantio-selectivities. Notably, an unexpected anti-selective carbo-carboxylation is observed in the sp2-hybrid carbo-electrophile-initiated reductive carboxylation of alkynes. Mechanistic studies including DFT calculation elucidate the origin of chiral induction and anti-selectivity in vinyl-carboxylation of alkynes.