On New Staudinger Type Reactions of Phosphorus Centered Biradicaloids, [P(μ‐NR)]₂ (R = Ter, Hyp), with Ionic and Covalent Azides

Abstract

Phosphorus centered biradicaloids of the type [P(μ‐NTer)]2 [R = Ter = terphenyl = 2,6‐bis(2,4,6‐trimethylphenyl)phenyl, Hyp = tris(trimethylsilyl)silyl] were treated with covalent (R‐N3) and ionic azides (AgN3 and Hg(N3)2). While the reaction with the ionic azides led exclusively to the formation of diazides, [N3P(μ‐NTer)]2, triaza‐diphospha‐pentadienes, RN=P–N(R')–P=NR, were observed in the reaction with covalent azides featuring a Staudinger type reaction followed by PN bond rearrangement reactions. This new Staudinger type mechanism as well as the structure, bonding and thermodynamics along different reaction paths are discussed based on DFT computations.

Reactions of main group compounds with azides forming organic nitrogen-containing species

“…In 2021, Schulz and co-workers studied the reactions of phosphorus-centered biradicaloids with ionic and covalent azides. 195 The reaction of P11a with ionic azides (AgN 3 or Hg(N 3 ) 2 ) led to the formation of diazide species P11a-P1 by oxidation (Scheme 124a), which also could be obtained by the reaction of phosphorus dihalides with AgN 3 . In contrast, treatment of P11a or P11b with the covalent azide (MesN 3 or DipN 3 ) afforded the triaza-diphospha-pentadiene P11a-P2 and P11b-P1 in 41% and 22% yields, respectively, with the evolution of N 2 (Scheme 124b).…”