Iron-catalysed, general and operationally simple formal hydrogenation using Fe(OTf)₃ and NaBH₄

An operationally simple and environmentally benign formal hydrogenation protocol has been developed using highly abundant iron(III) salts and an inexpensive, bench stable, stoichiometric reductant, NaBH₄, in ethanol, under ambient conditions. This reaction has been applied to the reduction of terminal alkenes (22 examples, up to 95% yield) and nitro-groups (26 examples, up to 95% yield). Deuterium labelling studies indicate that this reaction proceeds via an ionic rather than radical mechanism.