Double metal cyanides as heterogeneous Lewis acid catalysts for nitrile synthesis via acid-nitrile exchange reactions.

A series of transition metal-based double metal cyanides (DMCs) were studied as catalysts for the synthesis of nitriles via acid-nitrile exchange reaction. The best nitrile yields were obtained with Co3[Co(CN6)]2 DMC, which proved to be a versatile, stable, reusable and highly active catalyst, exhibiting an activity comparable to that of homogeneous Lewis acid catalysts.