Phosphide, dilithium

The direct synthesis of a phosphetane ring by the alkylation-cyclization method using dilithium phosphide and 1,3-dihalopropane resulted in a low yield (13%), because of thermally favored chain-forming side reactions and the instability of the final product in the reaction mixture (Equation 25) <1996OM1301>. 

Phosphide anions are excellent nucleophiles and are very reactive to alkylating agents and metal-lophosphine derivatives are of importance as phosphide transfer agents. Lithium diphenyl phosphine can be used to prepare water-soluble phosphines. Dilithium phenyl phosphine can be used in the synthesis of phosphiranes, phosphetanes and so forth (Chapter 6). Lithium bis(trimethylsilyl)phos-phanide, LiP(SiMe3)2, is useful for the synthesis of compounds with P-Si linkages (Figure 9.11). 

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