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

Precise synthesis of carboxylic acids via catalytic carboxylation with CO 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 CO. A variety of valuable axially chiral carboxylic acids are obtained with good yields and high chemo-, regio-, Z/E and enantio-selectivities. Notably, an unexpected anti-selective carbo-carboxylation is observed in the sp-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.