The Trityl-Cation Mediated Phosphine Oxides Reduction

Reduction of phosphine oxides into the corresponding phosphines using PhSiH3 as a reducing agent and Ph3C+[B(C6F5)(4)](-) as an initiator is described. The process is highly efficient, reducing a broad range of secondary and tertiary alkyl and arylphosphines, bearing various functional groups in generally good yields. The reaction is believed to proceed through the generation of a silyl cation, which reaction with the phosphine oxide provides a phosphonium salt, further reduced by the silane to afford the desired phosphine along with siloxanes.

Automated summary

The reduction of phosphine oxides into phosphines using PhSiH3 and Ph3C+[B(C6F5)(4)](-) is highly efficient and yields a broad range of secondary and tertiary alkyl and arylphosphines with various functional groups. The reaction is believed to proceed through the generation of a silyl cation and subsequent reduction by the silane.