Pd(0) catalyzed intramolecular Heck reaction: a versatile route for the synthesis of 2-aryl substituted 5-, 6-, and 7-membered O-containing heterocycles

An efficient and convenient method for the synthesis of 2-aryl substituted tetrahydropyran, tetrahydrofuran, and oxepine derivatives via intramolecular palladium catalyzed cyclization is developed. The two exo-cyclic double bonds at adjacent carbon atoms in these ring systems could serve as potential dienes for cycloaddition reactions.