Ball-Milling-Enabled Zn(OTf)₂-Catalyzed Friedel–Crafts Hydroxyalkylation of Imidazo[1,2-a]pyridines and Indoles

Abstract

A facile and efficient synthetic method for the construction of C3-hydroxyalkylated imidazo­[1,2-a]­pyridines and indoles by a Zn­(OTf)2-catalyzed Friedel–Crafts hydroxyalkylation of imidazo­[1,2-a]­pyridines and indoles with carbonyl compounds under mechanochemical conditions is reported. Good product selectivity, shorter reaction time, ambient reaction temperature, tolerance of a wide range of functional groups, broad substrate scope, moderate to good yield of products, and scalability are the salient features of the developed methodology.

Ru(II)-Catalyzed [4 + 2]-Annulation of 2-Alkenyl/Arylimidazoles with N-Substituted Maleimides and 1,4-Naphthoquinones: Access to Imidazo-Fused Polyheterocycles

“…Deng et al demonstrated a Rh­(III)-catalyzed [4 + 2]-annulation of 2-arylbenzo­[ d ]­imidazoles with maleimides to construct cis -dihydrobenzimidazo­[2,1- a ]­isoquinolines . In a continuation of our interest in the synthesis of N -heterocyclic compounds under transition-metal catalysis, herein, we report a ruthenium-catalyzed C–H/N–H annulation of 2-alkenyl/2-arylimidazoles with N- substituted maleimides and 1,4-naphthoquinone to construct a series of imidazo-fused polyheterocyclic frameworks (Scheme ).…”

KBrO3-Promoted Cross-Dehydrogenative Coupling Reaction: An Odorless Regioselective Sulfenylation of Imidazoheterocycles in Water

“…Imidazoheterocycle motifs possess various useful biological and medicinal activities . Particularly, the sulfenylation of imidazo­[1,2- a ]­pyridine derivatives has gained attention in recent years.…”