Palladium-Catalyzed Generation of ortho-Quinone Methides. A Three-Component Synthesis of L-Shaped Dimeric Steroidal Scaffolds.

A series of hybrid dimers having orthogonal steroidal cores bridged by a chroman ketal moiety were obtained by Pd-catalyzed three-component reactions of steroid alkynols, 2-formylestradiol 17-monoacetate, and methyl orthoformate, via ortho-quinone methide intermediates. One of the obtained L-shaped scaffolds showed an inefficient crystal packing featuring large channels within the crystal array. Monte Carlo simulations indicate that these voids preferentially allocate n-hexane, opening the way to explore further applications of similar organic crystalline materials as selective hosts for small molecules.