A series of 2, 3, 4-trisubstituted and 1, 2, 3, 4-tetrasubstituted pyrroles were synthesized via [3+ 2] cycloaddition of α-acyl ketene dithioacetals (or related substrates) with commercially available propargylamines as 1, 3-dipoles in water. Most of the reactions can be performed in the absence of an external base. The reaction of secondary amine (N-methylprop-2-yn-1- amine) with α-acyl ketene dithioacetals showed different reaction behaviours depending ...
