Phosphinocyclopentadienid via Cyclopentadienylphosphid/ Phosphinocyclopentadienide via Cyclopentadienylphosphide

Abstract

<jats:title>Abstract</jats:title><jats:p>Lithiumorganyls RLi (R = Me, Bu, Ph) add to (PhP)<jats:sub>5</jats:sub> in successive degradation and disproportionation equilibria depending on the ratio of the reactants. At -70 °C (R = Me) disproportionation is blocked and (PhP)<jats:sub>4</jats:sub>R<jats:sup>-</jats:sup> and (PhP)<jats:sub>3</jats:sub>R<jats:sup>-</jats:sup> can be detected. With excess RLi m onophosphides PhPR<jats:sup>-</jats:sup> are formed. </jats:p><jats:p>CpNa with the help of a crown ether degrades (PhP)<jats:sub>5</jats:sub> or substitutes cyanide from PhPCN<jats:sup>-</jats:sup> to give an equilibrium mixture of (PhP)<jats:sub>n</jats:sub>Cp<jats:sup>-</jats:sup> anions, which stabilize by proton shifts: In case of n = 1 and 2 a shift from the Cp unit to the terminal phosphorus results in the formation of the phenylphosphino- and diphenyldiphosphino-cyclopentadienide anion, in case of n = 3 two proton shifts within the Cp unit result in a cyclopenteno-l,2,3-triphospholene allylic anion.</jats:p>

Contributions to the chemistry of phosphorus. 218. Monocyclic and polycyclic phosphines

“…167 The degradation of (PPh)s with LiPh was reinvestigated a few years ago, as were the analogous reactions with LiBun and LiMe. 168 The reaction patterns are more or less identical. In the case of LiNR2 (R = Et, Pr'), the phosphides Li(PPh)"NR2 (n = 2, 3) are formed169 and with CN-the monophosphide P(Ph)CNis obtained.170…”

“…The corresponding primary products from the reaction of (PPh)3 with NaCp, Na(PPh)"Cp (n = 1-3), undergo stabilization through shifts of protons of the Cp ring. 168 Cyclotetraphosphanes with two to four adjacent Me3Si substituents react with LiR (R = Me, Bun) via ring opening and formation of terminal, monolithiated tetraphosphides which subsequently undergo isomerization and disproportionation reactions. 171 The ring degradation of monocyclophosphanes by stoichiometric amounts of halogens to yield the corresponding dihalo(organo)phosphanes has been known for a long time.6 (PR)n + nX2 -> nRPX2 (29) n = 3-5; X = Cl, Br, I On iodination or bromination of (PPh)3 in a molar ratio of 2.5:1, it is possible to isolate the intermediates I(Ph)PP(Ph)I172 and Br(Ph)PP(Ph)Br, respectively.…”

Molecules that we made: An essay on phosphorus chemistry

“…Delicate equilibria were found to be derived from the nucleophilic degradation of (PhP) 5 [124,126,132,133]. Such equilibria often allow the transfer of one or more phenylphosphinidene units to another reagent, and there is certainly a lot of unused potential in them.…”

Rhodium-Catalyzed Insertion Reaction of PhP Group of Pentaphenylcyclopentaphosphine with Acyclic and Cyclic Disulfides

“…Among various (RP) n compounds, pentaphenylcyclopentaphosphine (PhP) 5 ( 1 ) can readily be synthesized by the reaction of dichlorophenylphosphine and magnesium . However, its chemical reactivity has not been significantly examined, except for a few examples: alkylation of 1 with alkyllithium gave mixtures of oligophosphide Li­(PhP) n R ( n = 1–4); substitution of 1 with 1,2-dichlorobenzene in the presence of a stoichiometric amount of potassium provided 1,2,3-triphenyl-1,2,3-triphosphaindan; addition of 1 to diphenylacetylene at 240 °C gave a mixture of 1,2-diphenyl-1,2-diphosphetene and pentaphenyltriphospholene; and carbene-phosphinidene adducts formed via the addition of 1 to carbene such as N -heteroacyclic carbenes and bicyclic (alkyl)­(amino)­carbene . Woollins reagent obtained from 1 and selenium powder are also used in organic synthesis .…”