Efficient One-Pot Synthesis of 2,3-Dihydropyrimidinthiones via Multicomponent Coupling of Terminal Alkynes, Elemental Sulfur, and Carbodiimides

An organolithium-promoted multicomponent reaction (MCR) involving readily available terminal alkynes, elemental sulfur, and carbodiimides has been achieved for the first time. This MCR offers an atom-economic route to 2,3-dihydropyrimidinthiones which are difficult to access by other means via an interesting and useful C=N double bond cleavage and an sp(3) C-H bond functionalization of carbodiimides.