Reactivity of hexachlorocyclotriphosphazene towards alkyl-lithium reagents

Abstract

Reactions of (NPCl₂)₃ with LiMe or LiBu^t and an excess of propan-2-ol at –60 °C in tetrahydrofuran lead to complex reaction mixtures containing cyclic derivatives in 80–90% yield. The composition of each reaction mixture has been analyzed by ¹H and ³¹P n.m.r. spectrometry. The n.m.r. data thus obtained indicate the presence of a novel cyclophosphazene, viz. NP(H)OPrⁱ(NPCl₂)₂ and several alkyl-substituted cyclophosphazenes. Typical compounds were isolated and characterized as their 2,2,2-trifluoroethoxy-substituted derivatives. The structural characterizations of the reaction products are described together with the appropriate reaction pathways, based on an initial metalhalogen exchange process.