Regioselective Preparation of Hetero-2,3-Diarylpropionic Acids

A stepwise copper-catalyzed boracarboxylation then palladium-catalyzed Suzuki-Miyaura cross-coupling methodology was developed to access 2,3-diarylpropionic acid derivatives regioselectively by pre-setting the position of the carboxylic acid in the first catalytic reaction. This method provides a single regioisomer compared to the traditional hydrocarboxylation strategies that afford both regioisomers. Pharmaceutical potential was demonstrated in synthesizing a glucagon receptor antagonist drug in 3-steps (31% overall yield) from the commercially available 4-tert-butylstyrene.