PhSiH3

PhSiH3, commonly called phenylsilane, is an organosilicon compound with the formula C6H8Si. It consists of a phenyl group bound to a silicon atom bearing three hydride ligands (SiH3), giving a tetrahedral silicon center. PhSiH3 is a colorless liquid that is sensitive to air and moisture and is typically handled under inert atmosphere in dry solvents.

PhSiH3 is prepared and sold for laboratory use, and it can be synthesized in situ by the reduction of phenyltrichlorosilane (PhSiCl3) with a hydride donor such as lithium aluminum hydride. It is also accessible through other hydrosilylation-based routes. In practice, it is stored in tightly closed containers under inert gas.

In organic synthesis, PhSiH3 functions primarily as a hydride donor in catalytic hydrosilylation reactions. Under the influence of transition-metal catalysts (for example platinum- or rhodium-based systems), it adds across carbon–carbon multiple bonds to form organosilicon products such as alkyl- or vinylsilanes. These products can be further transformed, for instance by oxidation or cross-coupling, or used as silyl-protected intermediates. PhSiH3 is also employed, under appropriate catalytic conditions, as a mild reducing agent for certain carbonyl compounds in combination with activators or co-catalysts.

Safety and handling notes: PhSiH3 is flammable and reacts with water and oxygen to release hydrogen gas and silicon-containing byproducts. It should be handled in a fume hood with appropriate shielding from ignition sources and stored under inert gas in moisture- and air-free conditions.

Related compounds include other alkyl- and aryl-substituted silanes used in hydrosilylation and as reducing agents in organic synthesis.