Thiazolidinedione–Isatin Conjugates via an Uncatalyzed Diastereoselective Aldol Reaction on Water

An uncatalyzed aldol reaction of N-substituted thiazolidinediones with isatin derivatives has been developed “on water” to afford a new class of pharmacologically important thiazolidinedione–isatin conjugates in excellent yields and diastereoselectivities. The isatin–thiazolidine conjugate undergoes a catalyst-free stereoselective transfer aldol reaction on water. Single-crystal X-ray studies reveal that the aldol products can self-assemble to form supramolecular DNA “zipper” like structures through intermolecular hydrogen bonds and aromatic π–π interactions.