Controlled monohalogenation of phosphonates Part IV. Selective synthesis of monohalomethylenediphosphonates

Bogdan Iorga (1) , Philippe Savignac (1)

1 DCPH - Laboratoire Hétéroéléments et Coordination

The preparation of monohalogenated tetraalkyl methylenediphosphonates 5 has been studied. Upon electrophilic halogenation lithiated chloro-, bromo-and iodomethylenediphosphonates 4a-c are selectively prepared from unprotected lithiated methylenediphosphonates 2 whereas the protected ones 3 are unreactive. Condensation of lithiated dihalogenomethanes with diethyl chlorophosphate 7 leads to the formation of lithiated chloro-, and bromomethylenediphosphonates 4a,b. A possible reaction pathway via intermediate carbenoids is proposed.

Mots clés: electrophilic halogenation; SNP(V) reaction; phosphonate; halogenomethylenediphosphonate

Domaines: Chimie organique

Bogdan Iorga, Philippe Savignac. Controlled monohalogenation of phosphonates Part IV. Selective synthesis of monohalomethylenediphosphonates. Journal of Organometallic Chemistry, 2001, 624 (1-2), pp.203-207. ⟨10.1016/s0022-328x(00)00889-5⟩. ⟨hal-03161510⟩