Hydrogenations and Deuterium Labeling with Aluminum-based Metal Alloys Under Aqueous Conditions

Advances in the application of aluminum-based metal alloys in the hydrogenation as well as deuteration of a broad range of organic compounds are reviewed. The use of the Al-based alloys allows, and in fact favors, the reaction to be carried out in aqueous medium, which is a major step forward for reduction reactions given the recent need for environmentally benign reaction design. The Al content of the alloy, used as reductant, reacts with water in situ providing hydrogen and a Raney-type catalyst, thus the alloy serves as both a hydrogen generator as well as a hydrogenation catalyst. The applications can easily be extended to the preparation of isotope labeled materials by the simple use of D2O. The simpilicity and efficacy of the method is illustrated by the reduction of a variety of compound groups including carbonyl compounds, aromatic and heteroaromatic rings, aryl halides, phenols, nitriles, nitroso or nitro compounds, just to name a few. The work includes three chapters; (i) the major types of commercially available Al-based alloys and their basic characteristics and condition for their use, (ii) the discussion of recent results related to the hydrogenation of major functional group types and finally (iii) the application of these alloys in the preparation of deuterium labeled compounds.