Stereoselective synthesis of α,β-unsaturated carboxylic acids from alkynes using the Fe(CO)5/t-BuOK/AcOH/CH2Cl2 reagent system

Enantioselective Synthesis of Chiral Carboxylic Acids from Alkynes and Formic Acid by Nickel-Catalyzed Cascade Reactions: Facile Synthesis of Profens

We report a stereoselective conversion of terminal alkynes to α-chiral carboxylic acids using a nickel-catalyzed domino hydrocarboxylation-transfer hydrogenation reaction. A simple nickel/BenzP* catalyst displayed high activity in both steps of regioselective hydrocarboxylation of alkynes and subsequent asymmetric transfer hydrogenation. The reaction was successfully applied in enantioselective preparation of three nonsteroidal anti-inflammatory profens (>90 % ees) and the chiral fragment of AZD2716.

Cp2TiCl2-catalyzed hydrocarboxylation of alkynes with CO2: formation of α,β-unsaturated carboxylic acids

Cp₂TiCl₂-catalyzed hydrocarboxylation of alkynes with CO₂ (atmospheric pressure) has been reported. A range of alkynes were transformed to the corresponding α,β-unsaturated carboxylic acids in high yields with high regioselectivity.