Direct Catalytic Synthesis Of Beta-(C3)-Substituted Pyrroles: A Complementary Addition To The Paal-Knorr Reaction

The synthesis of beta-(C3)-functionalized pyrroles is a challenging task and requires a multistep protocol. An operationally simple direct catalytic synthesis of beta-substituted pyrroles has been developed. This one-pot multicomponent method combined aqueous succinaldehyde as 1,4-dicarbonyl, primary amines, and isatins to access hydroxyl-oxindole beta-tethered pyrroles. Direct synthesis of the beta-substituted free NH-pyrrole is the central intensity of this work. DFT-calculations and preliminary mechanism investigation support the possible reaction pathway.