Regioselective Synthesis of 2,3,4- or 2,3,5-Trisubstituted Pyrroles via [3,3] or [1,3] Rearrangements of O-Vinyl Oximes.

O-Vinyl oximes, generated by Ir-catalyzed isomerization of O-allyl oximes, undergo efficient cyclization to afford 2,3,4- trisubstituted pyrroles via [3,3] rearrangement or 2,5-di- and 2,3,5-trisubstituted pyrroles via [1,3] rearrangement.