PHOSPHORUS-CONTAINING METALLAMACROCYCLES

The four phosphorus-zirconium-containing macrocycles 4a-d, PhP(Y)[N(Me)N=C(H)C6H4OM-(Cp)2OC6H4C(H)=NNMe]2P(Y)Ph (M = Zr), were prepared via [2 + 2] cycloaddition reactions involving dimethylzirconocene, Cp2ZrMe2, and phosphodihydrazones 2a, b and 3a, b, PhP(Y)[N(Me)N=C(H)C6H4OH]2 (2a, meta OH, Y = S; 2b, meta OH, Y = 0; 3a, para OH, Y = S, 3b, para OH, Y = O). Addition of dimethyltitanocene, Cp2TiMe2, to 3a led to the macrocyclic [2 + 2] cycloadduct 4e. Phosphonium metallacycles 6c,d possessing either P-SMe or P-OSiMe3 groups were prepared by reacting 4c or 4d with methyl trifluoromethanesulfonate or trimethylsilyl trifluoromethanesulfonate respectively. p-Hydroxy phosphodihydrazones 3a,b when reacted with dimethyl- or diphenyldichlorosilanes led to the phosphorus-silicon-containing macrocycles 8a-c, PhP(Y)[NMeN=C(H)C6H4OSiR2-OC6H4C(H)=NNMe]2P(Y)Ph (R = Me, Ph), arising from [2 + 2] cyclocondensations.