Résumé
The reaction of ArLi
1 (Ar = [C
6H
3(CH
2NMe
2)
2-2,6]) with Ph
2PCl affords the phosphane
2 which, on treatment with HCl, gives rise to the monoprotonated ammonium salt
3, even in the presence of an excess of HCl.
2 reacts with MeI to give exclusively the phosphonium salt
4. Reaction of
1 with PhPCl
2 gives the stabilized phosphenium ion [ArPPh]
+Cl
−
6. This ion is reduced by LiAlH
4 in ArPHPh
9, which undergoes hydride abstraction on treatment with trityl cation, giving the same ionic phosphorus species. This unusual reaction is an example of increased reactivity of a P
H bond resulting from hypercoordination at the phosphorus atom.