The reduction of unsaturated hydrocarbons is a fundamental
synthetic transformation. Over the last hundred years, the ubiquity
of alkenes and alkynes in synthetic, petroleum, and natural products
chemistry has led to the development of numerous methods
for their reduction. Today, alkenes and alkynes can be reduced to
the corresponding alkanes using several principal approaches, each
of which offers certain advantages.1,2 The most common of these
approaches is direct hydrogenation using an external source of
molecular hydrogen and, typically, a finely divided metal catalyst.
As an alternative, catalytic transfer hydrogen methods that make
use of solvent or an additional reagent as the hydrogen source have
also been widely employed for the reduction of alkenes and alkynes.
Recently, several enzymatic, biochemical methods have
been described for the reduction of alkenes,3–6 though this approach
is somewhat limited by the generally poor water solubility
of most hydrocarbons. Another approach to the reduction of unsaturated
hydrocarbons is the application of hydride reagents such as
lithium aluminum hydride (LiAlH4), triethylsilane (Et3SiH), and sodium
borohydride (NaBH4).