Regioselective 2-alkylation of indoles with α-bromo esters catalyzed by Pd/P,P=O system

Abstract A palladium-catalyzed 2-alkylation of indoles with α-bromo esters is developed by employing a P,P=O ligand. The method features excellent regioselectivities, mild reaction conditions, and good functional group compatibility. The employment of the P,P=O ligand as well as 4A molecular sieves were crucial for the success of the transformation. Mechanistic studies indicate the reaction proceed through a radical pathway.