Reactions of allylzinc bromide with ethynylferrocene derived fluorinated cyclophosphazenes

•First reactions of organozinc reagents with cyclophosphazenes derived alkynes.•Reaction takes place stereospecifically on alkynes and not on the P–F bonds.•Alkyne derived phosphazenes were converted to terminal alkene derivative phosphazenes.•Phosphazene derivatives having multiple terminal alkene units were synthesized.

The use of organozinc reagents in the synthesis of terminal alkene derived cyclic halogenated phosphazenes has been explored by the reactions of allylzinc bromide and ethynylferrocene derived fluorophosphazenes. The reaction of monoethynylferrocene derived fluorophosphazene, [(FcCC)(F)PN](PNF2)2 (Fc = ferrocenyl) with allylzinc bromide in 1:6 M ratio resulted in the formation of [FcC(CH2CHCH2)CH(F)PN](PNF2)2 (1) and [FcC(CH2CHCH2)C (CH2CHCH2) (F)PN](PNF2)2 (2) having allyl groups attached to the alkenyl carbon close to the ferrocene moiety. A similar reaction of geminal bisethynylferrocene derived fluorophosphazene, [(FcCC)2PN](PNF2)2 with allylzinc bromide in 1:4 M ratio resulted in the formation of [{FcC(CH2CHCH2)CH}2PN](PNF2)2 (3) while a reaction in 1:14 M ratio resulted in the formation of compound 3 along with the unsymmetrically substituted triallyl derivative, [{FcC(CH2CHCH2)C(CH2CHCH2)} {FcC(CH2CHCH2)CH}PN] (PNF2)2 (4). The new compounds 1–4 were characterized by 1H, 13C{1H}, 31P{1H}, 19F{1H}, IR and HRMS studies. Compounds 1 and 3 have also been structurally characterized by single-crystal X-ray diffraction studies.

Graphical abstractThe first reactions of allylzinc bromide with mono and bis geminal ethynylferrocene derived fluorophosphazenes resulted in products having one to three allyl groups stereospecifically substituting on the alkyne units with no reaction on the P–F bonds of the fluorophosphazene.Figure optionsDownload full-size imageDownload as PowerPoint slide