Domino 1,3-dipolar cycloaddition/ring-opening/ring-cleavage: synthesis of trisubstituted pyrrole and chiral dihydropyrrole-3-carbaldehydes

Abstract

A unique approach has been developed to synthesize trisubstituted 1H-pyrrole-3-carbaldehydes using 4-methyl thiazolium salts, α,β-unsaturated aldehydes, and organocatalysts via a domino 1,3-dipolar cycloaddition/ring-opening/C–S and C–N bond cleavage reaction sequence. This methodology has been successfully extended for the asymmetric synthesis of enantioenriched trisubstituted-4,5-dihydro-1H-pyrrole-3-carbaldehydes employing chiral amine organocatalysts with high efficiency (up to 98% ee, >20 : 1 d.r.).