A Boryl‐Substituted Diphosphene: Synthesis, Structure, and Reaction with n‐Butyllithium To Form a Stabilized Adduct by pπ‐pπ Interaction

Abstract

Ab oryl-substituted diphosphene was synthesized through the nucleophilic borylation of PCl 3 with ab orylzinc reagent, followed by areduction with Mg. Acombined analysis of the resulting diboryldiphosphene by single-crystal X-ray diffraction, DFT calculations,a nd UV/Vis spectroscopy revealed a s-electron-donating effect for the boryl substituent that was slightly weaker than that of the 2,4,6-tri-tert-butylphenyl (Mes*) ligand. The reaction of this diboryldiphosphene with n BuLi afforded ab oryl-substituted phosphinophosphide that was,i nc omparison with the thermally unstable Mes*substituted diaryldiphosphene,s tabilized by a p-electronaccepting effect of the boryl substituent.Scheme 1. Synthesis of diboryldiphosphene 2.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under http://dx.

Stabilizing P≡P: P22–, P2⋅–, and P20 as bridging ligands

“…Starting from P4 or the coupling of P1-synthons, P2 adducts with strong carbene, boryl, vinyl or silylene donors could be isolated (Figure 1). 23,24,25,26,27,28,29,30,31 However, Lewis base coordination injects electron density into π * MOs, thereby reducing the P≡P bond order and resulting in products with diphosphene or even diphosphane character. 32,33 Triply bonded diphosphorus might alternatively be stabilized by coordination of Lewis acids to the nonbonding terminal lone pairs: Isolable P2 transition metal complexes were obtained by P4 activation with low-valent transition metal complexes, 34,35,36,37 or decarbonylative coupling of phosphaketene complexes (Figure 1).…”

NHC‐Coordinated Diphosphene‐Stabilized Gold(I) Hydride and Its Reversible Conversion to Gold(I) Formate with CO2

“…The structure of the NHC‐stabilized Au I phosphinophosphide 4 was finally confirmed by X‐ray diffraction on single crystals (Figure ). The P−P bond distance of 4 is 2.218(1) Å and thus slightly longer than in the one of the reported boryl substituted lithium phosphinophosphide (2.1775 Å) …”

Phosphine-catalysed reductive coupling of Dihalophosphanes

“…50 The thermal decomposition products have been shown to be the triphosphirane (PDip) 3 ( 3) and the dimerization product (PDip) 4 (4) in S7, Figure S48). The cyclic voltammogram of 2 in THF (0.1 M [nBu 4 N][PF 6 ]) showed a reversible reduction event at −2.10 V (vs. Cp 2 Fe/Cp 2 Fe + ; Figure S31), which is higher than that of (Mes*P) 2 (−2.36 V), 53 and ([sB]P) 2 (−2.24 V) [sB] = (H 2 CNDip) 2 B) 54 suggesting a lower LUMO level in 2 compared to these species. With compound 2 accessible we became interested in its reactivity towards N-heterocyclic carbenes (NHCs).…”