A regioselective palladium-free protocol for accessing unsymmetrical biaryls through ring transformation of 6-aryl-α-pyrones

A regioselective synthesis of unsymmetrical biaryls with electron withdrawing or donating substituents is described and illustrated by carbanion-induced ring transformation of 6-aryl-α-pyrones with methoxyacetone in excellent yield. Our methodology is an alternative to classical organometal-catalyzed aryl–aryl coupling reactions and can be applied to the synthesis of functionally demanding naphthyl biaryls for the development of new ligands for asymmetric synthesis.