3084-50-2Relevant academic research and scientific papers
A practical lewis base catalyzed electrophilic chlorination of arenes and heterocycles
Maddox, Sean M.,Nalbandian, Christopher J.,Smith, Davis E.,Gustafson, Jeffrey L.
supporting information, p. 1042 - 1045 (2015/03/30)
A mild phosphine sulfide catalyzed electrophilic halogenation of arenes and heterocycles that utilizes inexpensive and readily available N-halosuccinimides is disclosed. This methodology is shown to efficiently chlorinate diverse aromatics, including simple arenes such as anthracene, and heterocycles such as indoles, pyrrolopyrimidines, and imidazoles. Arenes with Lewis acidic moieties also proved amenable, underscoring the mild nature of this chemistry. Lewis base catalysis was also found to improve several diverse aromatic brominations and iodinations.
Mechanistic study of precursor evolution in colloidal group II-VI semiconductor nanocrystal synthesis
Liu, Haitao,Owen, Jonathan S.,Alivisatos, A. Paul
, p. 305 - 312 (2008/04/18)
The molecular mechanism of precursor evolution in the synthesis of colloidal group II-VI semiconductor nanocrystals was studied using 1H, 13C, and 31P NMR spectroscopy and mass spectrometry. Tri-n-butylphosphine chalcogenides (TBPE; E = S, Se, Te) react with an oleic acid complex of cadmium or zinc (M-OA; M = Zn, Cd) in a noncoordinating solvent (octadecene (ODE), n-nonane-d20, or n-decane-d22), affording ME nanocrystals, tri-n-butylphosphine oxide (TBPO), and oleic acid anhydride ((OA)2O). Likewise, the reaction between trialkylphosphine selenide and cadmium n-octadecylphosphonic acid complex (Cd-ODPA) in tri-n-octylphosphine oxide (TOPO) produces CdSe nanocrystals, trialkylphosphine oxide, and anhydrides of n-octadecylphosphonic acid. The disappearance of tri-n-octylphosphine selenide in the presence of Cd-OA and Cd-ODPA can be fit to a single-exponential decay (kobs = (1.30 ± 0.08) × 10-3 s-1, Cd-ODPA, 260 °C, and kobs = (1.51 ± 0.04) × 10-3 s-1, Cd-OA, 117 °C). The reaction approaches completion at 70-80% conversion of TOPSe under anhydrous conditions and 100% conversion in the presence of added water. Activation parameters for the reaction between TBPSe and Cd-OA in n-nonane-d20 were determined from the temperature dependence of the TBPSe decay over the range of 358-400 K (ΔH? = 62.0 ± 2.8 kJ·mol-1, ΔS? = -145 ± 8 J·mol-1·K-1). A reaction mechanism is proposed where trialkylphsophine chalcogenides deoxygenate the oleic acid or phosphonic acid surfactant to generate trialkylphosphine oxide and oleic or phosphonic acid anhydride products. Results from kinetics experiments suggest that cleavage of the phosphorus chalcogenide double bond (TOP=E) proceeds by the nucleophilic attack of phosphonate or oleate on a (TOP=E)-M complex, generating the initial M-E bond.
Formation and structure of a novel zwitterionic phosphoniocyclopentenonide from Bu3P, DMAD and COS
Aitken, R. Alan,Lightfoot, Philip,Wilson, Neil J.
, p. 35 - 37 (2007/10/03)
Tributylphosphane, DMAD and carbonyl sulfide react in a 2:2:1 ratio to give Bu3PS and the crystalline adduct 2 which is stabilised by extensive delocalisation; the sulfur analogue 5 has also been obtained.
Reactivity of X3P compounds with elemental sulfur, carbon disulfide or both, to yield X3PS, X3RCS2 or X3P.Sn.CS2 adducts
Demarcq, Michel C.
, p. 307 - 320 (2007/10/03)
Kinetic constants k2 have been obtained for the reaction of sulfur with 25 PIII compounds in toluene or hexane. In the series PhnMe3-nP (n = 1-3) or PhnBu3-nP (n = 0-3), log k2 decreases linearly with Σχi (χi=Tolman's electronic parameter of each ligand on P), taken as a gauge for the donor strength of P. Dramatic deviations from additivity are observed for the series PhnP(OEt)3-n, PhnP(OEt)3-n, and BunP(OEt)3-n(n = 0-3); the deviation is smaller for PhnPCl3-n, and even smaller for PhnP(NEt2)3-n . The results are discussed in terms of P-coordination (PIV vs. PV), stability and geometry of the intermediate X3P.S8 or of the transition state leading to this adduct, emphasis being laid on the donor/acceptor character of the P site. A similar dependence on X governs the reactivity of X3P with S8, CS2 or both, to give X3PS, X3P.CS2 (binary red adduct) or X3P.Sn.CS2 (ternary yellow adduct) respectively; an explanation for this parallelism is proposed.
New Metal-Sulphur-Nitrogen Compounds from Reactions in Liquid Ammonia. The X-Ray Structures of trans-Bis(acetophenone dimethylhydrazone-Nα)-dichloropalladium(II) and 1N4>palladium(II)
O'Mahoney, Caroline A.,Parkin, Ivan P.,Williams, David J.,Woollins, J. Derek
, p. 1179 - 1186 (2007/10/02)
Reaction of Cl or Cl in liquid ammonia with or (L-L' = C-N ligand) gives and respectively; in some cases complexes containing S3N(1-) ligands were also obtained.An alternative route to complexes using is also reported.Reaction of S8-NH3(I) solutions with gives .The new complexes were characterised by microanalyses, i.r., n.m.r., and mass spectroscopy, and X-ray crystallography.
Absolute Rate Expressions for the Abstraction of Hydrogen by Primary, Secondary, and Tertiary Alkyl Radicals from Thiophenol
Franz, James A.,Bushaw, Bruce A.,Alnajjar, Mikhail S.
, p. 268 - 275 (2007/10/02)
Absolute rate expressions for the abstraction of hydrogen from thiophenol in nonane by tert-butyl, isopropyl, n-butyl, and n-octyl radicals were determined by kinetic absorption spectroscopy (KAS).Alkyl radicals were produced by photolysis of dialkyl disulfides or by photolysis of mixtures of di-tert-butyl peroxide and trialkylphosphine in the presence of thiophenol.Arrhenium expressions for alkyl radicals from the phosphine method from 255 to 355 K were as follows: n-butyl, log(k/M-1s-1)=(9.40+/-0.13)-(1.74+/-0.21)/θ, θ=2.303RT kcal/mol; isopropyl, log(k/M-1s-1)= (9.26+/-0.19)-(1.70+/-0.21)/θ; tert-butyl, log(k/M-1s-1)=(9.26+/-0.26)-(1.50+/-0.20)/θ.Rate constants at 298 K vary from 0.8E8 to 1.5E8 M-1s-1 for hydrogen-transfer reactions.
Synthetic, Structural, and Theoretical Studies on the Electron-Deficient Cubanes (RC5H4)4Ti4S4, (RC5H4)4V4S4, and +
Darkwa, James,Lockemeyer, John R.,Boyd, Peter D. W.,Rauchfuss, Thomas B.,Rheingold, Arnold L.
, p. 141 - 149 (2007/10/02)
Treatment of (MeCp)2V2S4 with PBu3 gives the electron-deficient (56e) cubane (MeCp)4V4S4 (1).Desulfurization of 1:1 mixture of (MeCp)2V2S4 and Cp2V2S4 gave a mixture of ring-substituted cubanes (MeCp)4-xCpxV4S4 (x = 1-4) while (MeCp)2V2S4 and Cp2V react to give exclusively (MeCp)2Cp2V4S4.Compound 1 has a triplet (S = 1) ground state, exhibits Curie-Weiss magnetic behaviour, and has a well-resolved isotropically shifted 1H NMR spectrum.Cyclic voltammetry (vs Ag/AgCl) established the following redox series: 1+/1 (772 mV), 1/1- (176 mV), and 1-/12- (-1281 mV).The salt (BF4) was prepared by the reaction of 1 and Ph3CBF4.The diamagnetic 52e cubanes (RCp)4Ti4S4 (R = Me(2), i-Pr) were prepared from (RCp)TiCl2(THF)x and (Me3Si)2S.The compounds 1, (BF4), and 2 were characterized by single-cristal X-ray diffraction.Compound 1 crystallized in the cubic space group p43n with a = 16.551 (3) Angstroem with Z = 6; 671 unique reflections were processed to a final R(F) = 5.31 (Rw(F) = 5.80).Compound (BF4) crystallized in the tetragonal space group I4 with a = 10.600 (3) Angstroem and c = 12.600 (3) Angstroem with Z = 2; 463 unique reflections were processed to a final R = 6.40 (Rw(F) = 6.55.Compound 2 crystallized in the orthorhombic space group Cmca with a = 1.412 (5), b = 17.293 (6), c = 24.503 (9) Angstroem with Z = 8; 558 unique reflections were processed to give R = 10.5 (Rw(F) = 12.6. 1 and + are extremely similar structurally; no bond distances differ by more than 0.03 Angstroem.The structure of 2 revealed two sets of Ti-Ti distances, four distances of 3.00 Angstroem and two of 2.93 Angstroem.Electronic structure calculations of Cp4V4S4 and + were performed by the scattered wave-Xα method.The ground-state configuration for the Cp4V4S4 metal bonding orbitals is a12e4t22.The t2 orbital is predicted to be nonbonding, consistent with the structural results.The bonding in 1, 1+, and 2 is discussed in light of recent results from other laboratories.
THIOALKYLTRIBUTYL- AND THIOALKOXYTRIPHENYLPHOSPHONIUM SALTS: PREPARATION AND APPLICATION TO THE SYNTHESIS OF THIOLESTERS AND UNSYMMETRICAL SULFIDES
Ohmori, Hidenobu,Maeda, Hatsuo,Konomoto, Kohichi,Sakai, Kiyoshi,Masui, Masaichiro
, p. 4473 - 4481 (2007/10/02)
Thioalkoxyphosphonium salts, Ph3PSR(1+)*ClO4(1-) (3) and Bu3PSR(1+)*X(1-) (X=ClO4 and BF4) (5), have been prepared from the corresponding tertiary phosphines and disulfides by simple procedures, which involve (i) constant current electrolysis in acetonitrile in the presence of either HClO4 (for 3) or PhCOOH and LiX (for 5), and (ii) stirring an equimolar mixture of a phosphine, a disulfide, PHCOOH, and LiX in acetonitrile at ambient temperature.For the preparation of 3, which have been reported as useful reagents for the synthesis of unsymmetrical disulfides, the electrochemical method is recomended, while for 5 the latter non-electrochemicl procedure gave better results.Reactions of the phosphonium salts 5 with carboxylic acidsand primary alcohols in benzene at ambient temperature gave thiolesters and unsymmetrical sulfides, respectively, in fair to excellent yields.Keywords - triphenylphosphine; tributylphosphine; disulfide; thioalkoxyphosphonium salt; thiolester; unsymmetrical sulfide
