Structure and reactivity of phosphorus-selenium heterocycles with peri-substituted naphthalene backbones

Abstract

Reaction of naphthalene-1.8-bis(dichlorophosphine) with sodium selenide and selenium gives naphthalene-1,8-diyl)-1,3,2,4-diselenoxodiphosphetane 2,4-diselenide (27), a molecule with its four-membered PSePSe ring spanned by a naphthalene-1,8-diyl backbone. 27 was fully characterised, including by X-ray diffraction. Unusually, the reaction yielded not only 27, but also a polymeric or oligomeric material that was selenium deficient, containing significant amount of species with phosphorus atoms not fully oxidised to P(V). Reactions of the selenium deficient material with simple alcohols afforded two 1,2-diphosphaacenaphthenes, which were structurally characterised.

Reactivity Profile of a Peri-Substitution-Stabilized Phosphanylidene-Phosphorane: Synthetic, Structural, and Computational Studies

“…An interesting observation from the reactions with chalcogens is that they proceed under relatively mild conditions, indicating that 1 is rather reactive in comparison to (for example) tertiary phosphines or cyclic oligophosphines. 24 In line with decreasing oxidizing power of elements on going down the Group 16, lower oxidation state phosphorus centers become more prevalent at the bottom of the group.…”

Formation and Reactivity of Phosphorus–Selenium Rings

“…Selenium-deficient systems are also accessible, and very recently a naphthalene-backbone system NapP 2 Se 4 (Nap = naphthalene-1,8-diyl), which appears to contain significant amounts of oligomeric or polymeric materials 27-29 with low selenium content, has also been prepared (Scheme 8). [21] The presence of extremely bulky organic substituents results in either monomeric diselenoxophosphoranes 30-32 with a three-coordinate pentavalent phosphorus atom, [22][23][24] three-membered rings 33 and 34, [22,25] or eight-membered rings 35 and 36. [26] One selenadiphosphirane containing the pentamethylcyclopentadienyl substituent, which is neither particularly bulky nor electronically stabilizing, was isolated as stable species 37 and crystallographically characterized (Scheme 9).…”

Peri‐Interactions in 8‐Diphenylphosphino‐1‐bromonaphthalene, 6‐Diphenylphosphino‐5‐bromoacenaphthene, and Derivatives

“…Consequently, a vast number of 1,8-diphosphino-substituted naphthalenes-, (1,8-X 2 P) 2 -Nap, (D, X = R, H, Cl, OR, NR 2 ) has been prepared over the years. [49][50][51][52][53][54][55][56][57][58][59][60][61] Amongst those, 1,8-(Ph 2 P) 2 -Nap is the most prominent example, and has been utilized as chelating ligand for a number of transition metals. [62,63] Unlike B, the C-H lithiation of diphenylphosphinonaphthalene (E) [64] with various organolithium species is not a feasible strategy for the preparation of the intramolecularly coordinated 8diphenylphosphinonaphthylelement species 1-(R n E)-8-(Ph 2 P)-Nap (F), which is presumably the reason why the chemistry of these derivatives has not been extensively investigated.…”