18909-18-7Relevant articles and documents
A C2-Linked Bis-silene Formed without Using Metals and the Transformation into the Bis-silyl and Bis-silylium C4-Cumulenes
Chen, Yilin,Li, Jiancheng,Jiang, Wenjun,Zhao, Jinbo,Zhu, Hongping,Muhammed, Shahila,Parameswaran, Pattiyil,Roesky, Herbert W.
, p. 4282 - 4286 (2020)
Reaction of silylene L(Cl)Si: (1; L = PhC(NtBu)2) with 1,3-diyne Me3SiCCCCSiMe3produced bis-silene L(Cl)Si=C(SiMe3)CC(SiMe3)C=Si(Cl)L (2). This shows a route by oxidative coupling reaction to silenes. Reaction of 2 with AgOSO2CF3resulted in [L(Cl)(F3CO2SO)Si](Me3Si)C=C=C=C(SiMe3)[Si(OSO2CF3)(Cl)L] (3) and a silver mirror. From the reaction of 2 and B(C6F5)3were isolated compounds {[L(Cl)Si](Me3Si)C=C=C=C(SiMe3)[Si(Cl)L]}2+·2[ClB(C6F5)3]-(4) and {LSi[μ2-C2(SiMe3)(CCSiMe3)]}2(5). When 2 was treated with [Ph3C]+[B(C6F5)4]-, compounds [L2(Cl)Si]+[B(C6F5)4]-(6) and Ph2C=-cyclo-C(CH=CH)2CHCPh3(7) were formed. These reactions exhibit reduction of the polar Si=C bond to create unusual species of neutral and dicationic C4-cumulenes. The formation, bonding, and reactivity of compound 2 is explored by the computational quantum mechanical calculations.
A Base-Free Terminal Actinide Phosphinidene Metallocene: Synthesis, Structure, Reactivity, and Computational Studies
Zhang, Congcong,Hou, Guohua,Zi, Guofu,Ding, Wanjian,Walter, Marc D.
, p. 14511 - 14525 (2018)
The synthesis, structure, and reactivity of a base-free terminal actinide phosphinidene metallocene have been comprehensively studied. The salt metathesis reaction of the thorium methyl iodide complex Cp?2Th(I)Me (2; Cp? = η5-1,2,4-(Me3C)3C5H2) with Mes*PHK (Mes* = 2,4,6-(Me3C)3C6H2) in THF furnishes the first stable base-free terminal phosphinidene actinide metallocene, Cp?2Th═PMes* (3). Density functional theory (DFT) shows that the bonds between the Cp?2Th2+and [PMes*]2-fragments are more covalent than those in the related thorium imido complex. While the phosphinidene complex3shows no reactivity toward alkynes, it reacts with a variety of heterounsaturated molecules such as CS2, isothiocyanate, nitriles, isonitriles, and organic azides, forming carbodithioates, imido complexes, metallaaziridines, and azido compounds. These experimental observations are complemented by DFT computations.
Strong Evidence of a Phosphanoxyl Complex: Formation, Bonding, and Reactivity of Ligated Phosphorus Analogues of Nitroxides
Heurich, Tobias,Nesterov, Vitaly,Schnakenburg, Gregor,Qu, Zheng-Wang,Grimme, Stefan,Hazin, Khatera,Gates, Derek P.,Engeser, Marianne,Streubel, Rainer
, p. 14439 - 14443 (2016)
Facile access to [W(CO)5(Ph2P-OTEMP)] is used to initiate a study on the generation, properties, and reactions of transient phosphanoxyl complexes [MLn(R2PO)], the first example of which could be trapped via het
A Phosphine-Coordinated Boron-Centered Gomberg-Type Radical
Rosenthal, Amos J.,Devillard, Marc,Miqueu, Karinne,Bouhadir, Ghenwa,Bourissou, Didier
, p. 9198 - 9202 (2015)
The P-coordinated boryl radical [Ph2P(naphthyl)BMes]. (Mes=mesityl) was prepared by (electro)chemical reduction of the corresponding borenium salt or bromoborane. Electron paramagnetic resonance (EPR) analysis in solution and DFT cal
Synthesis and structure of triphenylmethyl derivatives of ytterbium 2+2- and 2+2-
Bochkarev, Leonid N.,Molosnova, Natalia E.,Zakharov, Lev N.,Fukin, Georgy K.,Yanovsky, Alexander I.,Struchkov, Yuri T.
, p. 101 - 108 (1995)
Ionic triphenylmethyl complexes of ytterbium 2+2- (1) and 2+- (2) have been synthesized by the reaction of Ph3CCl with ytterbium in THF.Complex 1 has also been prepared by the reaction of ytterbium with a dimer of triphenylmethyl radicals in THF.It was found that this reaction was catalyzed by ytterbium dihalides.According to X-ray diffraction result the crystal structures of 1 and 2 are composed of isolated ions.The2+ cation has an ideal octahedral coordination of the central Yb atom with the Yb-O distance of 2.390(7) Angstroem.The 2+ cation is a centrosymmetrical dimer in which each Yb atom is bonded to four oxygen atoms of THF molecules and two (THF)4Yb units are linked via two symmetrical μ-Cl bridges, both Yb-Cl distances being 2.715(4) Angstroem.The - anion in 1 and 2 has a propeller-type geometry with the planar environment of the central carbon atom (within 0.02 Angstroem in 1 and 0.006 Angstroem in 2).The Ph rings are rotated out of the average CC3 plane of the central fragment of - anion by 28.2 deg in 1 and by 26.6, 31.9, 33.7 deg in 2. Keywords: Ytterbium; Lanthanide complexes; Carbanions; Triphenylmethyl derivatives; X-ray diffraction
Trivalent Rare-Earth-Metal Bis(trimethylsilyl)amide Halide Complexes by Targeted Oxidations
Bienfait, André M.,Wolf, Benjamin M.,T?rnroos, Karl W.,Anwander, Reiner
, p. 5204 - 5212 (2018)
In contrast to previously applied salt metathesis protocols the targeted rare-earth-metal compounds Ln[N(SiMe3)2]2(halogenido) were accessed by oxidation of Ln(II) silylamide precursors. Treatment of Sm[N(SiMe3)3]2(thf)2 with 0.5 equiv of C2Cl6 or 0.25 equiv of TeBr4 in thf and crystallization thereof gave [Sm{N(SiMe3)2}2(μ-X)(thf)]2 (X = Cl, Br). A similar reaction/crystallization procedure performed with 0.5 equiv of 1,2-diiodoethane gave monomeric Sm[N(SiMe3)2]2I(thf)2. Switching to Yb[N(SiMe3)2]2(thf)2, the aforementioned oxidants generated monomeric five-coordinate complexes Yb[N(SiMe3)2]2X(thf)2 (X = Cl, Br, I). The reaction of Eu[N(SiMe3)2]2(thf)2 with 0.5 equiv of C2Cl6 in thf yielded the separated ion pair [Eu{N(SiMe3)2}3Cl][(thf)5Eu(μ-Cl)2Eu(thf)5]. Performing the chlorination in n-hexane led to oxidation followed by rapid disproportionation into EuCl3(thf)x and Eu[N(SiMe3)2]3. The bromination reaction did not afford crystalline material, while the iodination gave crystals of divalent EuI2(thf)5. Use of trityl chloride (Ph3CCl) as the oxidant in thf accomplished the Eu(III) species [Eu{N(SiMe3)2}2(μ-Cl)(thf)]2. In situ oxidation of putative [Tm{N(SiMe3)2}2(thf)x] using 0.5 equiv of C2Cl6 in thf followed by crystallization from n-hexane led to the formation of a mixture of [Tm{N(SiMe3)2}2(μ-Cl)(thf)]2 and Tm[N(SiMe3)2]3. Switching the oxidant to 0.5 equiv of 1,2-diiodoethane and crystallizing from thf repeatedly afforded the bis-halogenated complex Tm[N(SiMe3)2]I2(thf)3.
Synthesis of Bis(trityl)iron(II) and Formation of the Iron(0)-Stabilized o, o-Isomer of Gomberg's Dimer
Hayton, Trevor W.,Touchton, Alexander J.,Wu, Guang
supporting information, p. 4045 - 4049 (2021/12/13)
Treatment of Fe(OAc)2 in THF with 2 equiv of Li(CPh3) at -25 °C results in the formation of [Fe(ν5-CPh3)2] (1) in 22% yield. Complex 1 was characterized by X-ray crystallography, NMR spectroscopy, and 57Fe M?ssbauer spectroscopy and features an ν5 binding
Rapid Iron(III)?Fluoride-Mediated Hydrogen Atom Transfer
Doyle, Lorna M.,Gericke, Robert,McDonald, Aidan R.,Panda, Chakadola
supporting information, p. 26281 - 26286 (2021/11/12)
We anticipate high-valent metal–fluoride species will be highly effective hydrogen atom transfer (HAT) oxidants because of the magnitude of the H?F bond (in the product) that drives HAT oxidation. We prepared a dimeric FeIII(F)?F?FeIII(F) complex (1) by reacting [FeII(NCCH3)2(TPA)](ClO4)2 (TPA=tris(2-pyridylmethyl)amine) with difluoro(phenyl)-λ3-iodane (difluoroiodobenzene). 1 was a sluggish oxidant, however, it was readily activated by reaction with Lewis or Br?nsted acids to yield a monomeric [FeIII(TPA)(F)(X)]+ complex (2) where X=F/OTf. 1 and 2 were characterized using NMR, EPR, UV/Vis, and FT-IR spectroscopies and mass spectrometry. 2 was a remarkably reactive FeIII reagent for oxidative C?H activation, demonstrating reaction rates for hydrocarbon HAT comparable to the most reactive FeIII and FeIV oxidants.
Generation of a Ni3Phosphinidene Cluster from the Ni(0) Synthon, Ni(η3-CPh3)2
Touchton, Alexander J.,Wu, Guang,Hayton, Trevor W.
supporting information, p. 1360 - 1365 (2020/04/20)
Reaction of NiCl2 in THF with 2 equiv of Li(CPh3) at -25 °C results in formation of Ni(η3-CPh3)2 (1) in moderate yield. Complex 1 was fully characterized, which included analysis by X-ray crystallography. In the solid state, 1 features an η3 binding mode
Three-coordinate copper(II) alkynyl complex in C-C bond formation: The sesquicentennial of the glaser coupling
Warren, Timothy H.,Bakhoda, Abolghasem,Okoromoba, Otome E.,Greene, Christine,Boroujeni, Mahdi Raghibi,Bertke, Jeffery A.
supporting information, p. 18483 - 18490 (2020/11/27)
Copper(II) alkynyl species are proposed as key intermediates in numerous Cu-catalyzed C-C coupling reactions. Supported by a β-diketiminate ligand, the three-coordinate copper(II) alkynyl [CuII]-C≡CAr (Ar = 2,6-Cl2C6H3) forms upon reaction of the alkyne H-C≡CAr with the copper(II) tertbutoxide complex [CuII]-OtBu. In solution, this [CuII]-C≡CAr species cleanly transforms to the Glaser coupling product ArC≡C-C≡CAr and [CuI](solvent). Addition of nucleophiles R′C≡C-Li (R′ = aryl, silyl) and Ph-Li to [CuII]-C≡CAr affords the corresponding Csp-Csp and Csp-Csp2 coupled products RC≡C-C≡CAr and Ph-C≡CAr with concomitant generation of [CuI](solvent) and {[CuI]-C≡CAr}-, respectively. Supported by density functional theory (DFT) calculations, redox disproportionation forms [CuIII](C≡CAr)(R) species that reductively eliminate R-C≡CAr products. [CuII]-C≡CAr also captures the trityl radical Ph3C· to give Ph3C-C≡CAr. Radical capture represents the key Csp-Csp3 bond-forming step in the copper-catalyzed C-H functionalization of benzylic substrates R-H with alkynes H-C≡CR′ (R′ = (hetero)aryl, silyl) that provide Csp-Csp3 coupled products R-C≡CR via radical relay with tBuOOtBu as oxidant.
