Vitamin B1-based thiazol-2-ylidene–Ru(ii) complexes: recyclable transfer hydrogenation catalysts in water

In order to develop recyclable catalyst in water, vitamin B1 based Ru( ii )-NHC complexes (2–4) were synthesized and evaluated for transfer hydrogenation of ketones and aldehydes with an azeotropic mixture of HCOOH/Et 3 N in water. The complex,4 exhibited excellent catalytic activity and recyclability.