Visible Light‐Induced, Metal‐Free Denitrative [3+2] Cycloaddition for Trisubstituted Pyrrole Synthesis
作者:Bhupal S. Karki、Lalita Devi、Ayushi Pokhriyal、Ruchir Kant、Namrata Rastogi
DOI:10.1002/asia.201901068
日期:2019.12.13
A metal-free, regioselectivesynthesis of trisubstituted pyrroles has been developed through a formal [3+2] cycloaddition reaction between 2H-azirines and nitroalkenes under visible light/photoredox-catalyzed conditions. The reaction proceeds through 2H-azaallenyl radical addition on β-nitrostyrenes in a Michael fashion followed by a base-mediated denitration reaction. The directive group influence
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