Synthesis of multisubstituted pyrroles by ligand-controlled site-selective arylation and their transformation into multiarylated pyrrolines and pyrrolidines

Multisubstituted pyrroles were prepared by Pd-catalyzed site-selective arylation of 2,5-disubstituted 1H-pyrroles with aryl chlorides, triflates, or nonaflates. Site-selectivity of the reaction was controlled using appropriate ligands, and 2,2,5-trisubstituted 2H-pyrroles were synthesized via dearomative C2-arylation. Moreover, 2,3,5-trisubstituted 1H-pyrroles were successfully fabricated by direct C3-arylation. These arylations can be applied to the pharmaceuticals bearing aryl chloride moieties. Additionally, 2,2,5-triaryl-2H-pyrroles were converted into multiarylated pyrrolines and pyrrolidines, which will be useful in synthetic and medicinal chemistry.