Organocatalyst trityl chloride efficiently promoted the solvent-free synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-ones by in situ formation of carbocationic system in neutral media

A highly efficient and novel procedure for the preparation of 12-aryl-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-one derivatives via the one-pot three-component condensation of 2-naphthol with arylaldehydes and dimedone in the presence of catalytic amount of trityl chloride (TrCl) as a homogeneous organocatalyst under natural and solvent-free conditions is described. It is interesting that TrCl by in situ formation of trityl carbocation with inherent instability catalyzes the reaction. (C) 2012 Elsevier B.V. All rights reserved.