Synthesis of 14‐{[(Un)substituted phenyl] or alkyl}‐14 H ‐dibenzo[ a , j ]xanthenes Using Yb(OTf) 3 as an Efficient Catalyst under Solvent‐free Conditions

A series of 14‐{[(Un)substituted phenyl] or alkyl}‐14 H ‐dibenzo[ a , j ]xanthenes were prepared under solvent‐free conditions by Yb(OTf) 3 catalyzed condensation reactions of β ‐naphthol with various aldehydes. The process presented here is operationally simple, environmentally benign and has good to excellent yields. Furthermore, the catalyst can be recovered conveniently and reused efficiently.