Hydrogenation of imino bonds with half-sandwich metal catalysts

Imines can be reduced to afford synthetically important amines via a number of means, of which half-sandwich metal complex-effected reduction has gained particular prominence in the past one decade or so. This Feature Article aims to summarise the progress made with such metal catalysts, placing emphasis on our own work. The article covers transfer hydrogenation and hydrogenation, and finishes with a brief account of catalyst immobilisation and mechanistic understanding.