Synthesis of 1,3,5,2λ5-Triazaphosphinines by Intramolecular Cyclisation of (N-Cyanophosphorimidoyl)guanidines and Diguanidinophosphonium Chlorides

✍ Scribed by Nicolas Inguimbert; Lothar Jäger; Marc Taillefer; Matthias Biedermann; Henri-Jean Cristau

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 170 KB
• Volume: 2004
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200400217

✦ Synopsis

Abstract

The sodium phosphonium diylide Na[Ph~2~P(NCN)~2~] (3) − the first example of a stabilised phosphonium diylide − was synthesised by treatment of sodium diphenylphosphide with 2 equiv. of cyanic azide. Compound 3 reacted with alkyl‐ and arylammonium salts [RR′NH~2~]Cl {R = PhCH~2~, __t__Bu, Ph; R′ = H; RR′ = −[(CH~2~)~2~O(CH~2~)~2~]−}. Depending on the molar ratios (1:1 or 1:2), (N‐cyano‐P,P‐diphenylphosphorimidoyl)guanidines Ph~2~P(NCN)N=C(NH~2~)NRR′ (8) or diguanidinodiphenylphosphonium chlorides [Ph~2~P{N=C(NH~2~)NRR′}~2~]Cl (10) were formed. When molten, compounds 8 yielded new cyclic 1,3,5,2λ^5^‐triazaphosphinines 11. The fusion of compound 10 allowed the formation of the same 1,3,5,2λ^5^‐triazaphosphinines 11, along with the formation of NH~4~Cl or [PhNH~3~]Cl. A crystal structure analysis of 4‐amino‐6‐morpholino‐2,2‐diphenyl‐1,3,5,2λ^5^‐triazaphosphinine (11a) revealed an almost planar six‐membered ring for the 1,3,5,2λ^5^‐triazaphosphinine template. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)