Iron-Catalyzed Chemoselective Transfer Hydrogenation of α,β-Unsaturated Ketones Using HO as a Surrogate of Hydrogen.

Sustainable and highly economical iron-catalyzed chemoselective reduction of C═C of α,β-unsaturated ketones has been established under mild reaction protocols. Water is used as a green and abundant surrogate of hydrogen and is scarcely used in organic synthetic transformations as a source of hydrogen. The developed protocol offers a broad spectrum for chemoselective transfer hydrogenation of α,β-unsaturated ketones. Moreover, the method was found to be highly effective for aryl and ferrocenyl α,β-unsaturated ketones consisting of one or two double bonds and with multiple functionalities. Moreover, the present method avoids prolonged reaction time, provides a wide range of substrates with excellent yield, and circumvents the tedious chromatographic workup.