T3P-Promoted Synthesis of a Series of Novel 2-Aryl-3-phenyl-2,3,5,6-tetrahydro-4H-1,3-thiazin-4-ones

•T3P/pyridine promoted the reaction of imines with 3-mercaptopropionic acid.•2-Aryl-3-phenyl-2,3,5,6-tetrahydro-4H-1,3-thiazin-4-ones were readily prepared.•Both electron-withdrawing and -donating groups worked on the 2-aryl ring.•The reaction can be done as a 2-component reaction or as a 3-component reaction.