Polymethylhydrosiloxane (PMHS) is an easily handled, inexpensive, non-toxic, and mild reducing agent. Although relatively inert towards organic functionality, PMHS can transfer its hydride to a variety of metal catalysts (including Sn, Ti, Zn, Cu, and Pd), which can then participate in a wide range of reductions. Alternatively, when made hypercoordinate by the action of fluoride or other nucleophiles, PMHS can act directly as a reducing agent. PMHS is attractive as a substitute for more expensive or hazardous silanes or siloxanes and as the stoichiometric reductant in catalytic organotin-mediated processes.
