Thiazolinium salt: an efficient catalyst for the Mukaiyama reaction

Abstract Mukaiyama aldol reactionbetween benzaldehydeand Danishefsky diene is promoted by ionic liquid-type salts. Hence, thiazolinium salts have been found to be the most efficient for this transformation. On a mechanistic point of view, only the Mukaiyama process is observed without any hetero Diels–Alder cycloaddition. In some cases, cyclisation of the Mukaiyama adduct occurred without addition of TFA. Interestingly, the thiazolinium catalyst can be recycled at least 10 times without loss of activity.