Phosphines by reduction

Preparation of Phosphines by Reduction.- A procedure for the reduction of phosphine oxides using trichlorosilane in inert... 

The approach of Horner et al. is shown in Scheme 4, The macrocyclic phosphonium salts may be converted to phosphine oxides with alkali (yields 30-85%) or to phosphines by reduction using LiAlH4 (yields 80-90%).91 It was found that dilution did not increase yields. 

Tertiary phosphine oxides are also produced as significant by-products in several of the reactions of phosphines that have been noted previously, including the Wittig olefination and the conversions of alcohols to haloalkanes with triphenylphosphine as an adjunct reagent. The tertiary phosphine oxides produced in such reactions present a problem in chemical economics, as they themselves possess little chemical utility. The phosphine may be regenerated, but several steps are required, as previously noted with preparations of phosphines by reduction (see Section 3.2). 

Preparation of Phosphines by Reduction.- Trichlorosilane continues to find application for the preparation of chiral phosphines from the corresponding chiral phosphine oxides. This route has been used in the synthesis of the chiral, non-... 

Preparation of Phosphines by Reduction. - The reduction of phosphine oxides in the final stage of phosphine synthesis remains a common strategy, with silane reagents often being used. Trichlorosilane has found application in the synthesis of the axially chiral systems (83), 73 (84), 7 (85), 75 the chiral... 

Preparation of Phosphines by Reduction. Trichlorosilane has been employed in the synthesis from the corresponding phosphine oxides of a range of interesting new systems, including the chiral diphosphine (46), the tricyclic phospholane... 

---