Base-Promoted Synthesis of N-H Free Pyrroles via net [3+2]-Cycloaddition

A base-promoted net-[3+2] cycloaddition of nitriles and 1-arylpropynes for the synthesis of pyrroles is described. The developed method provides convenient access to various 2,5-disubstituted or 2,4,5-trisubstituted pyrroles in 40% to 96% yields (32 examples). Among methods for the synthesis of pyrroles, the protocol presented here stands out for its convenience and atom-economy.