Indium triflate promoted one-pot multicomponent synthesis of structurally diverse 3-amino-imidazo[1,2-a]pyridines

An efficient, mild, and expeditious synthetic protocol has been developed for the synthesis of structurally diverse 3-amino-imidazo[1,2-a]pyridines, involving a three-component, one-pot cyclocondensation reaction of 2-aminobenzothiazole/2-aminoazines, ethyl isocyanoacetate/tert-butyl isocyanides, and pyrazole-3(4)-carbaldehyde/substituted aromatic carbonyl compounds in 45 min. using In(OTf) as a catalyst in toluene. Mild reaction conditions, high atom economy, operational simplicity, short reaction time, and structural diversity with high product conversion are among the advantages of the present synthetic protocol.