Imino-Diels–Alder and imino-aldol reactions catalyzed by samarium diiodide

In the presence of a catalytic amount of samarium diiodide in methylene chloride, aromatic imines react with Danishefsky diene to form tetrahydropyridine-4-ones in high yields. Under the same conditions, various imino-aldol reactions afford β-amino esters or β-amino ketones.