Base Controlled Three-Component Regioselective Synthesis of 2‑Imino Thiazolines and 2‑Thioxoimidazolin-4-ones

Base-controlled regioselective synthesis
of 2-imino thiazolines
and 2-thioxoimidazolin-4-ones was achieved to use a one-pot reaction
between chiral amino esters, isothiocyanates, and α-bromoketones/alkyl
halides. This three-component coupling reaction in acetonitrile provides
2-imino thiazolines, whereas the formation of 2-thioxoimidazolin-4-ones
was observed under basic conditions at ambient temperature. The corresponding
products were obtained in good to excellent yield with broad substrate
scope. Isolation of thiourea and thiohydantoin intermediates disclosed
the course of the reaction mechanism.