Samarium diiodide promoted reactions of a diphenyl α-iminoketone, a new synthesis of some pyrrole derivatives

The reduction of a diphenyl α-iminoketone with samarium diiodide has been studied. A fast two-electron transfer gives a samarium (Z)-enamidolate, which is protonated to afford an α-aminoketone or reacted with a variety of ketones to furnish pyrrole derivatives. Possible mechanisms are proposed.