Pd-Catalyzed Regioselective Hydrocarboxylation of Olefins Solely Using Formic Acid without Activator

A wide variety of linear carboxylic acids bearing various functional groups can be efficiently obtained in up to 99% yield, with >20:1 l/b ratios from a wide range of terminal or internal olefins via hydrocarboxylation with formic acid (HCO2H) using Pd(OAc)2 and 1,2-DTBPMB as catalyst under mild conditions. The reaction is performed in a relatively simple manner without the need for any additional activator or strong acid promoter.