The Third Hydrogenase: More Natural Organometallics

The [Fe]-hydrogenase, also known as “H 2 -forming methylenetetrahydromethanopterin dehydrogenase” (Hmd) or “iron−sulfur cluster-free hydrogenase”, is the third distinct class of hydrogenase enzyme to be discovered. In the presence of its carbocation substrate, it catalyzes the reversible cleavage of dihydrogen into H + and H −, placing the later concomitantly onto the substrate molecule. This review describes the emerging chemistry behind this fascinating enzyme.