Highly regio-, stereo-, and chemoselective Diels–Alder reaction of monothiomaleimide, an ambident CS and CC dienophile

Abstract

The thiocarbonyl group of monothiomaleimide 1 serves as a more reactive dienophile than the electron-deficient CC double bond in the same molecule for the Diels–Alder reaction with dienes 2c–g and provides ortho-endo products 3 exclusively or predominantly over the other possible adducts 4–10.