NaCl as Catalyst and Water as Solvent: Highly E-Selective Olefination of Methyl Substituted N-Heteroarenes with Benzyl Amines and Alcohols.

Oxidative coupling of benzylamines and alcohols with methyl substituted N-heteroarenes such as quinolines and quinoxalines has been achieved using chloride, a sea abundant anion as the catalyst for practical synthesis of a wide range of E-disubstituted olefins in aqueous medium. Detailed mechanistic studies and control experiments were carried out to deduce the reaction mechanism which indicated that in situ formed ClO2- is the active form of the catalyst. We have successfully carried out a 1 g scale reaction using this methodology, and five pharmaceutically relevant conjugated olefins were also synthesized by this method in moderate to good yields.