Phosphorus compounds are ubiquitous in the chemical sciences, finding applications throughout industry and academia. Of particular interest to synthetic chemists are organophosphorus compounds, which contain P-C bonds. However, state-of-the-art processes for the synthesis of these important materials rely on an inefficient, stepwise methodology involving initial oxidation of white phosphorus (P 4 ) with hazardous chlorine gas and the subsequent displacement of chloride ions. Catalytic P 4 organofunctionalisation reactions have remained elusive, as they require multiple P-P bond breaking and P-C bond formation events to break down the P 4 core, all of which must occur in a controlled manner. Herein, we describe an efficient transition metalcatalyzed process capable of forming P-C bonds from P 4 . Using blue light photocatalysis, this method directly affords valuable triarylphosphines and tetraarylphosphonium salts in a single reaction step.The academic, industrial and societal importance of phosphorus chemistry is difficult to overstate. Phosphorus is one of the six essential 'biogenic elements' required in large quantities by every living organism, and synthetic phosphorus compounds find myriad industrial and commercial applications due to their diverse array of useful chemical, physical and biological properties. 1 This importance is reflected in the fact that white phosphorus (P 4 ) is currently produced on an estimated scale of >1 Mt / year. 2 P 4 is by far the most reactive and industrially-relevant form of elemental phosphorus, and acts as the common precursor from which effectively all synthetic phosphorus-containing species are ultimately Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

[Ar′SnCo]2 (1, Ar′ = C6H3-2,6{C6H3-2,6-iPr2}2), a rare metal–metal bonded cobalt–tin cluster with low-coordinate tin atoms, was prepared by the reaction of [K(thf)0.2][Co(1,5-cod)2] (cod = 1,5-cyclooctadiene) with [Ar′Sn(μ-Cl)]2. This reaction illustrates a promising synthetic strategy to access uncommon metal clusters. The structure of 1 features a rhomboidal Co2Sn2 core with strong metal–metal bonds between tin and cobalt and a weaker tin–tin interaction. Reaction of 1 with white phosphorus afforded [Ar′2Sn2Co2P4] (2), the first molecular cluster compound containing phosphorus, cobalt and tin.

The first homoleptic cobalt phosphanido complex [K(thf) ][Co{1,2-(PtBu ) C B H } ] (1) was prepared by an unprecedented oxidative P-P bond addition of an ortho-carborane-substituted 1,2-diphosphetane to cobalt(-I) in [K(thf) ][Co(η -cod) )] (cod=1,5-cycloctadiene). Compound 1 is a rare distorted tetrahedral 3d complex with a low-spin ground state configuration. Magnetic measurements revealed that the complex is diamagnetic between 2 to 270 K in the solid state and at 298 K in [D ]THF solution. Based on DFT calculations, the unusual singlet ground state is caused by the strong σ-donor and moderate π-donor properties of the bis(phosphanido) ligand.

The homoleptic 1,3-diphosphacyclobutadiene sandwich complex [Co(h 4 -1,3-P 2 C 2 tBu 2 ) 2 ] À behaved as av ersatile and highly flexible metalloligand toward Ni 2 + ,R u 2 + , Rh + ,a nd Pd 2 + cations, formingarange of unusual oligonuclear compounds. The reactiono f[ K(thf) 2 {Co(h 4 -1,3-P 2 C 2 tBu 2 ) 2 }] with [Ni 2 Cp 3 ]BF 4 initially afforded the s-complex [CpNi{Co(h 4 -1,3-P 2 C 2 tBu 2 ) 2 }(thf)] (2), which converted into [Co(h 4 -CpNi{1,3-P 2 C 2 tBu 2 -kP,kC})(h 4 -1,3-P 2 C 2 tBu 2 )] (3)b elow room temperature. The structure of 3 contains an unprecedented 1,4-diphospha-2-nickelacyclopentadiene moiety formed by an oxidative addition of al igand PÀCb ond onto nickel. At elevated temperatures, 3 isomerized to [Co(h 4 -CpNi{1,4-P 2 C 2 tBu 2 -k 2 P, P })(h 4 -1,3-P 2 C 2 tBu 2 )] (4), which features a1 ,3-diphospha-2-nickelacyclopentadiene unit. Transmetalation of [K(thf) 2 {Co(h 4 -1,3-P 2 C 2 tBu 2 ) 2 }] with [Cp*RuCl] 4 (Cp* = C 5 Me 5 )a fforded tetranuclear[ (Cp*Ru) 3 (m-Cl) 2 {Co(h 4 -1,3-P 2 C 2 tBu 2 ) 2 }] (5), in which the [Co(h 4 -1,3-P 2 C 2 tBu 2 ] À aniona cts as ac helate ligand toward Ru 2 + .T he diphosphido complex [(Cp*Ru) 2 (m,h 2 -P 2 )(m,h 2 -C 2 tBu 2 )] (6)w as formed as ab yproduct. Pure compound 6 was isolated after prolonged heating of the reaction mixture. The reaction of [K(thf) 2 {Co(h 4 -1,3-P 2 C 2 R 2 ) 2 }] (R = tBu;a damantyl, Ad) with [RhCl(cod)] 2 (cod = 1,5-cyclooctadiene) afforded unprecedented p-complexes [Rh(cod){Co(h 4 -1,3-P 2 C 2 R 2 ) 2 }] (7:R = tBu; 8:R= Ad), in which one m:h 4 :h 4 -P 2 C 2 R 2 ligand bridges two metal atoms.T he pentanuclear complex [Pd 3 (PPh 3 ) 2 {Co(h 4 -1,3-P 2 C 2 tBu 2 ) 2 } 2 ]( 10), featuring aP d 3 chain andarare 1,4-diphospha-2-butene ligand,w as synthesized by reacting [K(thf) 2 {Co(h 4 -1,3-P 2 C 2 tBu 2 ) 2 }] with cis-PdCl 2 (PPh 3 ) 2 .T he redox properties of selected compounds were analyzed by cyclic voltammetry, whereas DFT calculations gave additional insighti ntot he electronic structures.The results of this study revealed several remarkable and previously unrecognized properties of the [Co(P 2 C 2 tBu 2 ) 2 ] À anion.Scheme1.Synthesis of complexes of type A. [7] [a] C. Rçdl,P rof. Dr.R.W olf

Complexes [(C 4 Me 4 )Co(CO) 2 {Co(P 2 C 2 tBu 2 ) 2 }](1, C 4 Me 4 = tetramethylcyclobutadiene) and [CpNi{Co(P 2 C 2 tBu 2 ) 2 }-(PPh 3 )] (2, Cp = cyclopentadienyl) were synthesized by transmetalating [Tl(thf ) 2 {Co(P 2 C 2 tBu 2 ) 2 }] with [(C 4 Me 4 )Co(CO) 2 I] and [CpNiBr(PPh 3 )]. Compounds 1 and 2 were fully characterized by X-ray crystallography, multinuclear NMR, UV/Vis, and IR spectroscopy, and elemental analysis. Their molecular structures show σ-coordination of one phosphorus atom of the [Co(P 2 C 2 tBu 2 ) 2 ]anion to the second metal atom (cobalt or nickel). Time-dependent density functional theory (TD-DFT) calculations were [a]

We report the synthesis of functionalized 1,3-bis(diphosphacyclobutadiene) complexes via the insertion of carbon-oxygen bonds of ethers, esters, aldehydes and amides into the P–Si bond of silylated complexes. Reactions of [K(tol)2][Co(η4-P2C2R2)2] [[K(tol)2][1a]: R=tBu, [K(tol)2][1b]: R=tPent (=tert-pentyl)] with Me3SiCl afford the trimethylsilyl-substituted derivatives [Co(η4-P2C2R2SiMe3)(η4-P2C2R2)] (2a,b, R=tBu, tPent). The Me3Si group is connected to a phosphorus atom of one of the 1,3-diphosphacyclobutadiene ligands. 2a,b readily react with organic substrates containing C–O single and C=O double bonds at ambient temperature. [Co(η4-P2C2R2(CH2)4OSiMe3)(η4-P2C2R2)] (3a, b) are formed by reaction of 2a, b with traces of THF. They can also be isolated by reacting the THF solvates [K(thf)2{Co(P2C2tBu2)2}] ([K(thf)2][1a]) and [K(thf)3{Co(P2C2tPent2)2}] ([K(thf)3][1b]) with Me3SiCl in toluene or THF. The adamantyl-substituted complex [Co(η4-P2C2Ad2(CH2)4OSiMe3)(η4-P2C2Ad2)] (3c) was prepared analogously from [K(thf)4{Co(P2C2Ad2)2}] and Me3SiCl. [K(thf)2][1a] reacts cleanly with Ph3SnCl affording [Co(η4-P2C2tBu2SnPh3)(η4-P2C2tBu2)] (4) in high yield. Reaction of 2a with styrene oxide affords [Co(η4-P2C2tBu2PhC2H3OSiMe3)(η4-P2C2tBu2)] (5) as a single regioisomer. By contrast, multinuclear NMR spectroscopic studies indicate mixtures of two isomeric insertion products 6/6′ and 7/7′, respectively, which result from the insertion of 1,2-epoxy-2-methylpropane and 1,2-epoxyoctane. Moreover, these monitoring studies show that reactions of 2a with acyclic ethers afford alkyl substituted complexes such as [Co(η4-P2C2tBu2Et)(η4-P2C2tBu2)] (8) and alkylsilyl ethers. Reaction of 2a with γ-butyrolactone gives [Co(η4-P2C2tBu2(CH2)3C(O)OSiMe3)(η4-P2C2tBu2)] (9) via cleavage of the endocyclic C–O single bond of the lactone. Benzaldehyde and acetone cleanly react with 2a to [Co(η4-P2C2tBu2CH(Ph)OSiMe3)(η4-P2C2tBu2)] (10) and [Co(η4-P2C2tBu2CMe2OSiMe3)(η4-P2C2tBu2)] (11), while the sterically more demanding ketones 3-pentanone and acetophenone selectively yield the known hydride complex [Co(η4-P2C2tBu2)2H] (A). Phenyl isocyanate reacts with 2a at elevated temperature to form [Co(η3-P2C2tBu2CON(Ph)SiMe3)(η4-P2C2tBu2)] (12) with a functionalized η3-coordinated ligand. [K(tol)2][1a], [K(tol)2][1b], 2a, 2b, 3a–c, 4, 5, and 9–12 were isolated and characterized by multinuclear NMR spectroscopy, UV/Vis spectroscopy and elemental analysis. [K(tol)2][1b], 2a, 2b, 3c, 4, 5, and 9–12 were additionally characterized by X-ray crystallography.

The synthesis andc haracterization of rare 1,3-diphosphacyclobutene transition-metal complexes is described. Reactions of the cobalt-hydride complex [Co(P 2 C 2 tBu 2 ) 2 H] (G)w ith nBuLi, tBuLi, or PhLi afforded [Li-(solv) x {Co(h 3 -P 2 C 2 tBu 2 HR)(h 4 -P 2 C 2 tBu 2 )}] (1:R = nBu, (solv) x = (Et 2 O) 2 ; 2:R = tBu, (solv) x = (thf) 2 ; 3:R = Ph, (solv) x = (Et 2 O)(thf) 2 ), with an h 3 -coordinated 1,3-diphosphacyclobutene ligand as ar esult of organyl-anion attacka to ne of the phosphorus atoms of the bis(1,3-diphosphacyclobutadiene) backbone. In contrast to the reactions with PhLi, the arylmagnesium compounds p-tolyl magnesium chloride and p-fluorophenyl magnesiumbromide deprotonate [Co(P 2 C 2 tBu 2 ) 2 H] to give the magnesium salt [Mg(MeCN) 6 ] [Co(h 4 -P 2 C 2 tBu 2 ) 2 ] 2 (4), whichc ontainsabis(1,3-diphosphacyclobutadiene)-cobaltatea nion. The [Co(h 4 -P 2 C 2 tBu 2 ) 2 ] À anions are well separated from the octahedral [Mg(MeCN) 6 ] 2 + cationi nt he molecular structure of 4.C ompound 1 reacts with Me 3 SiCl to give neutral [Co(h 3 -P 2 C 2 tBu 2 HnBu)(h 4 -P 2 C 2 tBu 2 SiMe 3 )] (5,5 2% yield) with an SiMe 3 group attached to one of the Pa toms of the previously unfunctionalized backbone. Figure 1. Previously reported derivatizations of 1,3-diphosphacyclobutadiene complexes through the attack of nucleophiles. [7][8][9] [a] C. Rçdl,P rof. Dr.R.W olf Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.Figure 2. a) FunctionalizationofF by treatment with electrophiles (previous work): i) HCl·Et 2 O;ii)MeI ;iii)Ph 2 PCl ;b)synthesis of anionic 1,3-diphosphacyclobutenec omplexes 1-3 by addition of lithium organyls to G (this work).

Die oxidative P‐P‐Bindungsaddition eines ortho‐Carboran‐substituierten 1,2‐Diphosphetans an Cobalt(−I) in [K(thf)0.2][Co(η4‐cod)2)] (cod=1,5‐Cycloctadien) ermöglichte die Darstellung des ersten homoleptischen Cobalt(III)‐Phosphanidokomplexes [K(thf)4][Co{1,2‐(PtBu)2C2B10H12}2] (1). Diese Verbindung ist ein seltenes Beispiel eines verzerrt tetraedrisch koordinierten 3d6‐Komplexes mit einem Low‐spin‐Grundzustand. Magnetische Messungen ergaben, dass 1 zwischen 2 und 270 K im Festkörper und bei 298 K in einer [D8]THF‐Lösung diamagnetisch ist. Dichtefunktionalrechnungen zeigten, dass der diamagnetische Grundzustand durch die starken σ‐Donor‐ und die moderaten π‐Donoreigenschaften der Bisphosphanidoliganden verursacht wird.