Enantioselective one-pot synthesis of 4H-chromene derivatives catalyzed by a chiral Ni(ii) complex.

ABSTRACT

A Ni(ii)-bis(oxazoline) complex and p-TSOH are used to form enantioenriched 4H-chromenes from ortho-quinone methides (o-QMs) and dicarbonyls, providing the desired products in up to 95% ee. The method is compatible with various ß-ketoester substrates, and the products obtained could be converted into biologically active 4H-chromene derivatives.