519-73-3Relevant articles and documents
Trityl tetraphenylborate as a reagent in organometallic chemistry
Straus, Daniel A.,Zhang, Cheng,Tilley, T. Don
, p. C13 - C17 (1989)
Trityl tetraphenylborate, prepared from trityl triflate and sodium tetraphenylborate, is shown to be a useful hydride and methyl anion abstraction reagent for organometallic compounds.It reacts with (η5-C5Me5)(PMe3)2RuMe to give the fulvene com
The stable pentamethylcyclopentadienyl cation
Lambert, Joseph B.,Lin, Lijun,Rassolov, Vitaly
, p. 1429 - 1431 (2002)
More than 100 years after the cyclopentadienyl anion appeared in the literature, the first cyclopentadienyl cation, the pentamethyl derivative C5Me5+, has now been prepared in a single step as the tetrakis(pentafluoropheny
Synthesis and characterization of a gold vinylidene complex lacking π-conjugated heteroatoms
Harris, Robert J.,Widenhoefer, Ross A.
, p. 6867 - 6869 (2015)
Abstract Hydride abstraction from the gold (disilyl)ethylacetylide complex [(P)Au{η1-C≡CSi(Me)2CH2CH2SiMe2H}] (P=P(tBu)2o-biphenyl) with triphenylcarbenium tetrakis(pentafluorophenyl)borate at -20 °C formed the cationic gold (β,β-disilyl)vinylidene complex [(P)Au=C=CSi(Me)2CH2CH2Si(Me)2]+B(C6F5)4- with ≥90% selectivity. 29Si NMR analysis of this complex pointed to delocalization of positive charge onto both the β-silyl groups and the (P)Au fragment. The C1 and C2 carbon atoms of the vinylidene complex underwent facile interconversion (ΔG≠=9.7 kcal mol-1), presumably via the gold π-disilacyclohexyne intermediate [(P)Au{η2-C≡CSi(Me)2CH2CH2Si(Me)2}]+B(C6F5)4-. Good as gold: Cationic gold (β,β-disilyl)vinylidene complex 1 was generated by addition of a pendant silylium ion to the C≡C bond of a gold acetylide complex (see scheme, P=PtBu2(o-biphenyl)). The vinylidene C1 and C2 atoms of 1 undergo facile interconversion, presumably via a π-disilacyclohexyne intermediate. 29Si NMR analysis of 1 indicates delocalization of positive charge onto both the β-silyl groups and the (P)Au fragment.
N-Heterocyclic Phosphenium Dihalido-Aurates: On the Borderline between Classical Coordination Compounds and Ion Pairs
Nickolaus, Jan,Schlindwein, Simon H.,Nieger, Martin,Gudat, Dietrich
, p. 1849 - 1854 (2017)
2-Bromo- and 2-chloro-1,3,2-diazaphospholenes react with (tht)AuCl to afford isolable N-heterocyclic phosphenium (NHP) dihalido-aurates, which were characterized by analytical and spectroscopic data and in one case by a single-crystal X-ray diffraction study. The T-shaped metal coordination sphere found in the crystal consists of a pseudo-linear AuX2 unit that is perturbed by a weakly bound NHP unit. DFT studies indicate that the subunits interact mainly through electrostatic and dispersion forces, with negligible covalent contributions, and that the phosphenium dibromido-aurate is slightly more stable than an isomeric complex with an intact bromophosphane ligand. NMR studies reveal that the NHP-AuX2 pairs persist in solution but are kinetically labile and readily undergo halide scrambling. The hydride/fluoride exchange reaction between a secondary phosphane-AuCl complex and [Ph3C][BF4] implies that a gold complex with an intact 2-halogeno-1,3,2-diazaphospholene ligand may be more stable than its phosphenium dihalido-aurate isomer when covalent P–X bonding contributions are strengthened.
STOICHIOMETRIC HYDRODEHALOGENATION AND FORMYLATION OF ORGANIC HALIDES USING TETRACARBONYL COBALTATE(-I)
Ungvary, Ferenc,Marko, Laszlo
, p. 379 - 382 (1980)
Methanolic solutions of tetracarbonyl cobaltate(-I) in the presence of an acid bring about replacement of organic halogens by hydrogen or the formyl group.In general, hydrogenolysis is the main (often the only) reaction, but formylation becomes significant with aliphatic and benzyl halides.
Stable silylnitrilium ions
Bahr, Steven R.,Boudjouk, Philip
, p. 4514 - 4519 (1993)
Trityl tetrakis[bis(3,5-trifluoromethyl)phenyl]borate, Ph3C+B[3,5-(CF3)2C6H 3]4-, abstracts hydride from hydridosilanes, producing Ph3CH. Use of a weakly co
'Redox-switch' catalysis of C-C bond formation with H2: One-electron reduction of the trityl cation
Hembre,McQueen
, p. 65 - 67 (1997)
Different products are formed from the electron transfer reaction between the ruthenium hydride 1 and the trityl cation when 1 is employed as a 'redox-switch' catalyst or as stoichiometric reducing agent. In the first case 1 converts H2 into a one-electron reducing agent for C-C bond formation, thus yielding the product known as Gomberg's dimer. In contrast, only triphenylmethane is produced in the stoichiometric reactions, by an electron-transfer/hydride-transfer mechanism.
Superacid-catalyzed condensation of benzaldehyde with benzene. Study of protonated benzaldehydes and the role of superelectrophilic activation
Olah, George A.,Rasul, Golam,York, Chentao,Prakash, G. K. Surya
, p. 11211 - 11214 (1995)
Under superacid conditions benzaldehyde reacts readily with benzene to give triphenylmethane in high yield. Experimental evidence supports the involvement of diprotonated benzaldehyde in the reaction. Ab initio calculations at the correlated MP2/6-31G* le
Protonation of a Cobalt Phenylazopyridine Complex at the Ligand Yields a Proton, Hydride, and Hydrogen Atom Transfer Reagent
McLoughlin, Elizabeth A.,Waldie, Kate M.,Ramakrishnan, Srinivasan,Waymouth, Robert M.
, p. 13233 - 13241 (2018)
Protonation of the Co(I) phenylazopyridine (azpy) complex [CpCo(azpy)] 2 occurs at the azo nitrogen of the 2-phenylazopyridine ligand to generate the cationic Co(I) complex [CpCo(azpyH)]+ 3 with no change in oxidation state at Co. The N-H bond of 3 exhibits diverse hydrogen transfer reactivity, as studies with a variety of organic acceptors demonstrate that 3 can act as a proton, hydrogen atom, and hydride donor. The thermodynamics of all three cleavage modes for the N-H bond (i.e., proton, hydride, and hydrogen atom) were examined both experimentally and computationally. The N-H bond of 3 exhibits a pKa of 12.1, a hydricity of ΔG°H- = 89 kcal/mol, and a bond dissociation free energy (BDFE) of ΔG°H? = 68 kcal/mol in CD3CN. Hydride transfer from 3 to the trityl cation (ΔG°H- = 99 kcal/mol) is exergonic but takes several hours to reach completion, indicating that 3 is a relatively poor hydride donor, both kinetically and thermodynamically. Hydrogen atom transfer from 3 to 2,6-di-tert-butyl-4-(4′-nitrophenyl)phenoxyl radical (tBu2NPArO·, ΔG°H? = 77.8 kca/mol) occurs rapidly, illustrating the competence of 3 as a hydrogen atom donor.
Trapping of an NiII Sulfide by a CoI Fulvene Complex
Hartmann, Nathaniel J.,Wu, Guang,Hayton, Trevor W.
, p. 1765 - 1769 (2017)
The reaction of [LtBuNiII(SCPh3)] (LtBu = {(2,6-iPr2C6H3)NC(tBu)}2CH) with Cp*2Co yields a NiI cobaltocenium thiolate complex, [LtBuNiI(SCH2Me4C5)Co(Cp*)] (1), along with HCPh3. Formation of this complex is proposed to occur via the reaction of a transient NiII sulfide, [Cp*2Co][LtBuNiII(S)], with a CoI fulvene complex, [CoCp*(C5Me4CH2)]. The latter complex is formed in situ by reaction of [Cp*2Co]+ with [CPh3]?. Control experiments, as well as cyclic voltammetry measurements of 1, are used to support the proposed mechanism.
