The transformation of münchnones (mesoionic rings featuring the 1, 3-oxazolium-5-olate core) into their sulfur counterparts (1, 3-thiazolium-5-thiolates) by reaction with CS2, pioneered by Huisgen and his group in the early 1970s, has been re-investigated in detail by means of both experimental and theoretical methods. The synthetic strategy can be tuned to incorporate donor and acceptor groups in appropriate positions. Calculations of ...