H-Bond-Directing Organocatalyst for Enantioselective [4 + 2] Cycloadditions via Dienamine Catalysis

An efficient, highly regio- and stereoselective [4 + 2] cycloaddition reaction to generate tetrahydropyranopyrazole frameworks has been developed. To this end, a dienamine-based catalytic strategy that relies on the H-bond-directing effect of the hydroxy group of a dinaphthylprolinol-type aminocatalyst has been used. This enables the synthesis of multifunctionalized heterocyclic derivatives with three contiguous stereocenters in good yields and excellent enantioselectivities.