Basic ionic liquid promoted heterocyclization to access fused imidazopyridines

Ionic Liquids-Prompted Synthesis of Biologically Relevant Five- and Six-Membered Heterocyclic Skeletons

“…Efficient synthesis of fused imidazopyridines 74 (Scheme 31) in good yield using IL [BMIM][OH] both as solvent and catalyst for click cyclocondensation of N-methylisatin with 2-aminopyridine was also reported [144]. The IL was recovered and reused twice without significant decrease in product yield.…”

Polycyclic imidazo[1,2-a]pyridine analogs – synthesis via oxidative intramolecular C–H amination and optical properties

“…35,36 Only three inefficient synthetic method-ologies leading to our targeted 5H-pyrido[2′,1′:2,3]imidazo [4,5b]indoles were reported: Cadogan cyclization, [37][38][39] multicomponent Bienaymé reaction followed by N-arylation 40,41 and ionic liquid promoted cyclization of N-methylisatin and 2-aminopyridine. 42 The synthesis of a library of pyridoimidazoindoles and the analysis of the relationship between their structure and spectroscopic properties might open the door to their future optoelectronic applications. In this paper we propose a novel strategy towards this class of nitrogen containing heterocycles, with the key step being oxidative C-H bond amination.…”