Microwave-assisted synthesis of a 3-aminoimidazo[1,2-a]-pyridine/pyrazine library by fluorous multicomponent reactions and subsequent cross-coupling reactions

Microwave and fluorous technologies are employed to increase reaction speed and reduce separation time in solution-phase parallel synthesis of a substituted 3-amino-imidazo[1,2-a]pyridine and 3-aminoimidazo[1,2-a]pyrazine library. Multicomponent reactions of perfluorooctanesulfonyl-tagged benzaldehydes with 2-aminopyridines (or 2-aminopyrazines) and isocyanides are followed by Pd-catalyzed cross-coupling reactions with boronic acids or thiols to form biaryls or aryl sulfides. Reaction mixtures are purified by fluorous solid-phase extraction (F-SPE) or crystallization.