A molybdenum-catalyzed synthesis of N-(hetero)aryl pyrroles directly from inexpensive and commonly available (hetero)nitroarenes via reduction with pinacol and annulation with 1,4-dicarbonyls or cyclobutane-1,2-diols has been described. The process does not require an inert atmosphere and tolerates the presence of air and water. This non-noble catalytic system shows high chemoselectivity, allowing a diverse range of potentially reducible functional groups such as alkynes, alkenes, halogens, cyano, and carbonyls. Moreover, this strategy enables the reuse of a waste byproduct as reactant, facilitating the formation of challenging 1,4-dicarbonyls from accessible cyclobutane-1,2-diols used as reducing agents.
