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791-28-6Relevant articles and documents
Ketenimine and imine functions linked by an ethylene group. Intramolecular [4+2] cycloadditions leading to imidazo[1,2-b]isoquinolines
Alajarín, Mateo,Vidal, Angel,Tovar, Fulgencio,Sánchez-Andrada, Pilar,Bautista, Delia
, p. 9913 - 9918 (2003)
The intramolecular cyclization of imino-ketenimines where an ethylene or propylene chain is linking the nitrogen atoms of both functionalities is studied. The propylene tethered imino-ketenimines remain unchanged under thermal conditions, whereas their ethylene counterparts undergo a formal [4+2] cycloaddition, in which the ketenimine function acts as all-carbon diene and the imine as dienophile, to yield imidazo[1,2-b]isoquinolines. An X-ray crystal structure determination reveals that these cycloadducts incorporate an hydroxyl group at the benzylic carbon C10.
Examination of oxygen atom transfer reactivity of heteroscorpionate dioxo-Mo(VI) complexes: Geometric isomers, solvent effect, intermediates, and catalytic oxidation
Tran, Ba L.,Arita, Amy,Cooksy, Andrew L.,Carrano, Carl J.
, p. 45 - 51 (2016)
Heteroscorpionate-based [(L10O)MoO2Cl] and [(L3S)MoO2Cl] complexes containing an interchangeable third heteroatom donor have been utilized for the systematic investigation of oxygen atom transfer (OAT) reactivity. The detection of phosphoryl intermediates and products in the reaction pathway were probed by UV-Vis, mass spectrometry, and 31P NMR spectroscopy. The OAT reactivity of the metal complexes toward PPh3 were monitored by UV-Vis spectroscopy under pseudo-first order conditions. The sterically encumbered (L10O) ligand gives rise to isolable trans and cis isomers of [(L10O)MoO2Cl] allowing investigation into the role of geometry on OAT reactivity. The OAT reactivity of the cis isomer of (L10O)MoO2Cl demonstrated a dramatic solvent dependence, in which the reaction proceeded at a measureable rate only in pyridine. However, the trans counterpart reacted in all solvents and at much faster rates. The catalytic oxidation of PPh3 to OPPh3 by trans-[(L10O)MoO2Cl] and cis-[(L3S)MoO2Cl] complexes using DMSO as an oxygen donor was monitored by 31P NMR in DMF at 30 °C with rates, kcat = 4.26 × 10-5 s-1 and 5.28 × 10-5 s-1, respectively.
Regioselective Palladium-Catalyzed Heterocyclization-Sonogashira Coupling Cascades from 2-Alkynylbenzamides and Terminal Alkynes: Experimental and DFT Studies
Cruz, Francisco,Vaz, Belén,Vilar, Unai,Ortega, Aitor,Madich, Youssef,álvarez, Rosana,Aurrecoechea, José M.
, p. 3813 - 3826 (2018)
A regioselective heterocyclization-Sonogashira coupling cascade between 2-alkynylbenzamides and terminal alkynes is described. The reaction proceeds under Pd(II) catalysis, with air used as a terminal oxidant to regenerate the catalyst from the Pd(0) produced in the C-C coupling. The cascade process provides alkynyl-substituted isobenzofuranimine products in a single operation. These products are the result of a 5-exo O-cyclization, while products derived from the alternative 6-endo cyclization mode are observed in minor amounts. Two competing mechanisms have been considered to account for the observed results. Both involve heterocyclization, alkyne C-H activation, and reductive elimination steps but differ in the relative order of the first two. Control experiments using a preformed alkynylpalladium complex have shown that a mechanism starting with alkyne C-H activation is viable. On the other hand, DFT calculations indicate that the alternative cyclization-first mechanism is also competitive, particularly when PPh3 is used as ligand. Calculations also suggest that the exo cyclization is favored over the endo mode by the presence of PPh3 and σ-C Pd ligands in the activated complex undergoing cyclization.
Nucleophilic addition of azoles to triphenyl-(phenylethynyl)phosphonium bromide and base hydrolysis of the addition products
Bagdasaryan,Pogosyan,Panosyan,Asratyan,Indzhikyan
, p. 1324 - 1326 (2006)
Reactions of pyrazole, 3,5-dimethylpyrazole, imidazole, and 1,2,4-triazole with triphenyl(phenylethynyl)phosphonium bromide gave the corresponding 2-azolyl-2-phenylethenyl(triphenyl)phosphonium salts. Base hydrolysis of the addition products led to the formation of 2-azolyl-1,2-diphenylethyl(diphenyl) phosphine oxides. Nauka/Interperiodica 2006.
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Gutmann,Kunze
, p. 786,792 (1963)
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Interaction of 4,5-diphenyl-2,3-dihydro-2,3-pyrroledione with ethoxycarbonylmethylenetriphenylphosphorane: synthesis and crystal srtucture of 4,5-diphenyl-Z-2-ethoxycarbonylmethylene-2,3-dihydro-3-pyrrolone
Aliev, Z. G.,Maslivets, A. N.,Simonchik, O. L.,Konyukhova, T. G.,Andreichikov, Yu. S.,Atovmyan, L. O.
, p. 1496 - 1498 (1995)
1-Unsubstituted 4,5-diphenyl-2,3-dihydro-2,3-pyrroledione interacts with ethoxycarbonylmethylenetriphenylphosphorane regioselectively to give 4,5-diphenyl-Z-2-ethoxycarbonylmethylene-2,3-dihydro-3-pyrrolone.The crystal and molecular structure of the latter was studied ny X-ray analysis. - Keywords: 2,3-dihydro-2,3-pyrroledione, alkoxycarbonylmethylenetriphenylphosphorane, Wittig reaction, crystal and molecular structure
Oxygen Activation by Co(II) and a Redox Non-Innocent Ligand: Spectroscopic Characterization of a Radical-Co(II)-Superoxide Complex with Divergent Catalytic Reactivity
Corcos, Amanda R.,Villanueva, Omar,Walroth, Richard C.,Sharma, Savita K.,Bacsa, John,Lancaster, Kyle M.,MacBeth, Cora E.,Berry, John F.
, p. 1796 - 1799 (2016)
Bimetallic (Et4N)2[Co2(L)2], (Et4N)2[1] (where (L)3- = (N(o-PhNC(O)iPr)2)3-) reacts with 2 equiv of O2 to form the monometallic species (Et4N)[Co(L)O2], (Et4N)[3]. A crystallographically characterized analog (Et4N)2[Co(L)CN], (Et4N)2[2], gives insight into the structure of [3]1-. Magnetic measurements indicate [2]2- to be an unusual high-spin CoII-cyano species (S = 3/2), while IR, EXAFS, and EPR spectroscopies indicate [3]1- to be an end-on superoxide complex with an S = 1/2 ground state. By X-ray spectroscopy and calculations, [3]1- features a high-spin CoII center; the net S = 1/2 spin state arises after the Co electrons couple to both the O2?- and the aminyl radical on redox non-innocent (L?)2-. Dianion [1]2- shows both nucleophilic and electrophilic catalytic reactivity upon activation of O2 due to the presence of both a high-energy, filled O2- π? orbital and an empty low-lying O2- π? orbital in [3]1-.
Synthesis of fluorophosphoranes via the mitsunobu reaction
Harvey, Peta J.,Jenkins, Ian D.
, p. 9775 - 9778 (1994)
Treatment of triphenylphosphine with potassium hydrogen fluoride or hydrogen fluoridepyridine and diisopropyl azodicarboxylate in acetonitrile or tetrahydrofuran, at room temperature results in the clean formation of difluorotriphenylphosphorane. Analogous results were obtained with other phosphines such as tributylphosphine and tris(dimethylamino) phosphine.
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Hays,H.R.
, p. 4201 - 4205 (1968)
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Parshall
, p. 1669 (1968)
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Novel metallo-therapeutics of the NSAID naproxen. Interaction with intracellular components that leads the cells to apoptosis
Banti,Giannoulis,Kourkoumelis,Owczarzak,Kubicki,Hadjikakou
, p. 6848 - 6863 (2014)
Two new mixed ligand-silver(i) complexes of the anti-inflammatory drug naproxen (naprH) and triphenylphosphine (tpp) or tri(p-tolyl)phosphine (tptp) of formulae {[Ag(tpp)3(napr)](H2O)} (1) and [Ag(tptp) 2(napr)] (2) have b
Initiated pseudo-[3+2] cycloaddition of mixed phosphonium-iodonium ylides to acetonitrile
Matveeva,Podrugina,Pavlova,Mironov,Zefirov
, p. 2237 - 2239 (2008)
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Tri(3-pyridyl)- and Tri(4-pyridyl)phosphine Chalcogenides and Their Complexes with ZnTPP (TPP = Tetraphenylporphyrinate)
Dubován, Lea,P?llnitz, Alpár,Silvestru, Cristian
, p. 1521 - 1527 (2016)
The preparation, spectroscopic characterization (NMR and IR spectroscopy), and solid-state structures of tri(3-pyridyl)- and tri(4-pyridyl)phosphine chalcogenides (E = O, S, Se) as well as their ability to behave as ligands for ZnTPP (TPP = tetraphenylpor
Vanadyl complexes with dansyl-labelled di-picolinic acid ligands: Synthesis, phosphatase inhibition activity and cellular uptake studies
Collins, Juliet,Cilibrizzi, Agostino,Fedorova, Marina,Whyte, Gillian,Mak, Lok Hang,Guterman, Inna,Leatherbarrow, Robin,Woscholski, Rudiger,Vilar, Ramon
, p. 7104 - 7113 (2016)
Vanadium complexes have been previously utilised as potent inhibitors of cysteine based phosphatases (CBPs). Herein, we present the synthesis and characterisation of two new fluorescently labelled vanadyl complexes (14 and 15) with bridged di-picolinic acid ligands. These compounds differ significantly from previous vanadyl complexes with phosphatase inhibition properties in that the metal-chelating part is a single tetradentate unit, which should afford greater stability and scope for synthetic elaboration than the earlier complexes. These new complexes inhibit a selection of cysteine based phosphatases (CBPs) in the nM range with some selectivity. Fluorescence spectroscopic studies (including fluorescence anisotropy) were carried out to demonstrate that the complexes are not simply acting as vanadyl delivery vehicles but they interact with the proteins. Finally, we present preliminary fluorescence microscopy studies to demonstrate that the complexes are cell permeable and localise throughout the cytoplasm of NIH3T3 cells.
On the Reaction of N-Vinyliminophosphoranes with 2,4,6-Cyclooctatrienone. Intermediate Formation of 8-Azabicycloundeca-2,4,7,9-tetraene Ring System.
Nitta, Makoto,Kanomata, Nobuhiro
, p. 2401 - 2403 (1989)
The reaction of N-(1-phenylvinyl)iminotriphenylphosphorane and of (1,3,5-cycloheptatrienyl)iminotributylphosphorane with 2,4,6-cyclooctatrienone gave an intermediacy of 8-azabicycloundeca-2,4,7,9-tetraene derivatives, which underwent an intramolecular Diels-Alder reaction to construct a tetracyclic ring system.
SOME ASPECTS OF PYRIDINIUM FLUOROCHROMATE, C5H5NHCrO3F (PFC), OXIDATIONS, STOICHIOMETRY OF OXIDATION OF ALCOHOLS, EVIDENCE FOR OXYGEN TRANSFER, AND THE IDENTITY OF THE REDUCED CHROMIUM SPECIES
Bhattacharjee, Manabendra N.,Chaudhuri, Mihir K.,Purkayastha, Subrata
, p. 5389 - 5392 (1987)
Molar stoichiometry of the oxidation of n-butanol, iso-propanol, benzyl alcohol, or cyclohexanol involving pyridinium fluorochromate, C5H5NHCrO3F (PFC), in dichloromethane, has been evaluated to be 1:1.The facile oxidation of triphenylphosphine oxide by P
2-Diazoacetyl-2 H-azirines: Source of a Variety of 2 H-Azirine Building Blocks with Orthogonal and Domino Reactivity
Sakharov, Pavel A.,Novikov, Mikhail S.,Khlebnikov, Alexander F.
, p. 8304 - 8314 (2018)
A synthesis of 2-diazoacetyl-2H-azirines was developed starting from 2H-azirine-2-carbonyl chlorides, generated by Fe(II)-catalyzed isomerization of 5-chloroisoxazoles. 2-Diazoacetyl-2H-azirines easily undergo reactions characteristic of α-diazo ketones with preservation of the azirine ring. Reactions with hydrohalogenic, carboxylic, and p-toluenesulfonic acids provide novel 1-(3-aryl-2H-azirin-2-yl)-2-halo- and 2-(R-oxy)ethan-1-ones in good yields. The synthesized 2H-azirines can offer many possibilities for chemical manipulation in heterocyclic synthesis, due to the presence of highly reactive azirine and the exocyclic C(O)-CHN2 or C(O)-CH2X functionalities, which can show orthogonal or domino reactivity. The synthetic usefulness of the developed building blocks was demonstrated by the preparation of new types of heterocyclic dyads (azirine-oxazole, azirine-pyrazoline, azirine-thiazole, azirine-oxirane, pyrrole-oxazole) as well as an azirine chalcone analogue, 2-azidoacetyl-2H-azirine, and 2-diazoacetylaziridine derivatives.
One-pot three-component synthesis of bis[2-(methylthio)-7-oxothiazolo[ 4,5-d]pyrimidin-6(7H)-yl]benzenes
Fang, Zheng Dong,Fang, Di,Zheng, Jing
, p. 337 - 339 (2013)
Three-component reactions of ethyl 2-methylthio-4- [(triphenylphosphanylidene)amino] thiazole-5-carboxylate with aromatic diisocyanates and secondary amines produced novel bis[2-methylthio-7- oxothiazolo[4,5-d]pyrimidin-6(7H)- yl]benzenes in the presence
Special features of alkaline hydrolysis of 4-substituted buta-1,3-dienetriphenylphosphonium salts
Ovakimyan, M. Zh.,Gasparyan, G. Ts.,Bichakhchyan
, p. 1088 - 1092 (2015)
Alkaline hydrolysis of triphenylphosphonium salts containing 4-S-, N-, and O-substituted buta-1,3-diene group has been studied. 4-S-substituted phosphonium salts are hydrolyzed with formation of the corresponding diphenyl-1-phenyl-4-alkylsulfanylphosphoryl compounds, the products of anionotropic migration of the phenyl group. Under the same conditions, the 4-N- and O-substituted buta-1,3-diene phosphonium salts form triphenylphosphine oxide as the major product along minor diphenyl-4-N- or diphenyl-4-O-substituted buta-1,3-diene phosphine oxides.
Synthetic peptides caged on histidine residues with a bisbipyridyl ruthenium(ii) complex that can be photolyzed by visible light
Mosquera, Jesús,Sánchez, Mateo I.,Mascare?as, José L.,Eugenio Vázquez
, p. 5501 - 5504 (2015)
We report a light-sensitive histidine building block for Fmoc/tBu solid-phase peptide synthesis in which the imidazole side chain is coordinated to a ruthenium complex. We have applied this building block for the synthesis of caged-histidine peptides that can be readily deprotected by irradiation with visible light, and demonstrated the application of this approach for the photocontrol of the activity of Ni(ii)-dependent peptide nucleases. This journal is
Synthesis, characterisation, and oxygen atom transfer reactions involving the first gold(i)-alkylperoxo complexes
Collado, Alba,Gomez-Suarez, Adrian,Oonishi, Yoshihiro,Slawin, Alexandra M. Z.,Nolan, Steven P.
, p. 10745 - 10747 (2013)
The synthesis of a new class of organogold species containing a peroxo moiety is reported. Complexes [Au(IPr)(OOtBu)] and [Au(SIPr)(OO tBu)] have been synthesised via a straightforward methodology using the parent gold(i) hydroxide complexes as synthons. These complexes have been successfully used in oxygen-transfer reactions to triphenylphosphine.
127. Synthesis and 1H-, 13C-, and 57Fe-NMR Spectra of Mono- and Bis4-diene)iron>, and (η3-Allyl)tetracarbonyliron Trifluoroborate Complexes
Adams, Christoph M.,Cerioni, Giovanni,Hafner, Andreas,Kalchhauser, Hermann,Philipsborn, Wolfgang von,et al.
, p. 1116 - 1142 (1988)
A variety of mono- and bis4-diene)> complexes with alkyl, CH2OH, CHO, COCH3, COOR, and CN substituents on the 1,3-diene have been synthesized.Dienes with a (Z)-configurated terminal Me group show steric inhibition of metal complexation resulting in lower yields and formation of tetracarbonyl(η2-diene) and tricarbonyl(η4-heterodiene) complexes as additional products.Regioselective attack by C-nucleophiles at the carbonyl C-atom of the functional group with or without concomitant 1,3-migration of the Fe(CO)3 group was used to synthesize polyenes and isoprenoid building blocks as mono- or dinuclear Fe(CO)3 complexes.Wittig-Horner-type reactions of Fe(CO)3-complexed synthons result in stereospecific formation of (E)-configurated olefins.The 1H-, 13C-, and 57Fe-NMR spectra of 73 olefinic and allylic organoiron complexes are reported.H,H,C,H, and C,C coupling constants have been evaluated and are analyzed in terms of the geometry of the coordinated diene.The results are corroborated by the crystal structure of tricarbonyliron (34) which shows an unusual distortion of the (CH3)2C= group.The 57Fe-NMR chemical shifts extend over the ranges of 0-600 ppm for 4-diene)> complexes, 780-1710 ppm for 3-allyl)> and 3-allyl)> complexes, and 1270-1690 ppm for 4-enone)> complexes, relative to Fe(CO)5.
Autocatalytic-assisted photorelease of a sensitizer drug bound to a silica support
Bartusik, Dorota,Minnis, Mihaela,Ghosh, Goutam,Greer, Alexander
, p. 8537 - 8544 (2013)
The photorelease of a sensitizer from a fluorinated silica surface occurs by a reaction of singlet oxygen with the vinyl ether bond linker with scission of a dioxetane intermediate. Irradiation of the released sensitizer generates singlet oxygen, which accelerates the release of more sensitizer via an autocatalytic reaction. Sigmoidal behavior of sensitizer release in n-butanol and n-octanol occurs at an optimal temperature of 20 C. The photorelease efficiency was reduced at low temperatures, where the sensitizer was retained on the surface due to a long-lived dioxetane with inefficient scission, and also reduced at high temperatures, due to a slower reaction of 1O 2 with the vinyl ether bond. Immediate acceleration is a result of released sensitizer being used as a dopant to eliminate the induction step, further implicating an autocatalytic mechanism. However, the sigmoidal sensitizer release was not correlated to solvent viscosity, heat, or light from the dioxetane decomposition or to minor O2 solubility enhancements caused by the fluorinated silica. The mechanistic information collected here can be used to help control the pace of drug release; however, it remains to be seen whether an autocatalytic-based drug delivery system has an advantage to those with non-sigmoidal kinetics.
Sulfonation with inversion by Mitsunobu reaction: An improvement on the original conditions
Anderson, Neal G.,Lust, David A.,Colapret, Kay A.,Simpson, James H.,Malley, Mary F.,Gougoutas, Jack Z.
, p. 7955 - 7958 (1996)
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Dissociation of the P=C ylidic bond
Shevchenko, Igor,Rogalyov, Alexey,Rozhenko, Alexander B.,Roeschenthaler, Gerd-Volker
, p. 254 - 258 (2007)
The phosphorus ylides RPh2P=C(Mes)N=C(CF3) 2 [R = Ph, Ph2P(O)CH2] in solution undergo reversible dissociation of the P=C ylidic bond to give phosphanes RPh 2P and the carbene MesC(:)N=C(CF3)2. The latter can be trapped as its mesomeric nitrile ylide by treatment with cyclohexene or phenyl isocyanate to give cyclic addition products. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Irradiation with UV Light Accelerates the MigitaKosugiStille Coupling Reaction in Air
Ishikawa, Takumi,Iwai, Tomohiro,Masai, Hiroshi,Murata, Mako,Terao, Jun
supporting information, p. 124 - 126 (2022/02/14)
The Migita-Kosugi-Stille coupling reaction is a powerful method for the formation of carboncarbon bonds but often requires high temperatures that are not tolerated by all substrates. Herein, we report that irradiation with UV light accelerates this coupling reaction at room temperature in air in the presence of the commercially available PdCl2(PPh3)2 catalyst. This UVlight- assisted coupling reaction requires the presence of molecular oxygen, with mechanistic studies revealing that singlet oxygen is most likely involved in the reaction.
Nitric oxide generation study of unsymmetrical β-diketiminato copper(ii) nitrite complexes
Chand, Kuldeep,Chu, Yu-Cheng,Hsu, Sodio C. N.,Kao, Chai-Lin,Lin, Ya-Fan,Tsai, Ming-Li,Wang, Tzai-Wei
supporting information, p. 3485 - 3496 (2022/03/14)
β-Diketiminato copper(ii) L1CuCl-L4CuCl and their nitrite complexes L1Cu(O2N) and L2Cu(O2N) have been synthesized and characterized. X-ray analysis of the L1CuCl-L4CuCl complexes clearly reveals their mononuclear structure with a four-coordinated Cu(ii) center bound by one chloride and three nitrogen atoms of unsymmetrical β-diketiminato ligands. Cyclic voltametric analysis of the Cu(ii) complexes shows that the length of the pyridyl arm controls the Cu(ii)/Cu(i) redox process. DFT and EPR results confirm that the geometry of the Cu(ii) complexes is also controlled by the length of the chelating pyridyl arm. The oxygen atom transfer nitrite reduction of the Cu(ii) nitrite complexes leads to the formation of copper(i)-PPh3 and OPPh3 which were confirmed by 1H and 31P NMR. The length of the pyridyl arm of the copper(ii) nitrite complexes governs the NO-releasing ability. These findings illustrate the important bioinspired behaviour and NO generation from nitrite via oxygen atom transfer of the unsymmetrical β-diketiminato copper(ii) complexes as compared to symmetrical β-diketiminato copper(ii) complexes.
Quaternary Phosphonium Carboxylates: Structure, Dynamics and Intriguing Olefination Mechanism
Müller-Bunz, Helge,Muldoon, Jimmy,Nikitin, Kirill,Vetter, Anna C.
, (2022/01/12)
We have earlier shown how the Wittig chemistry can be done using novel Eigenbase phosphonium carboxylate reagents. Here we discuss the phenomenon of ion pairing, their solution tautomerism, solid-state structure, and mechanistic aspects of olefination. The results point to a complex process involving unfamiliar H-bond-driven ion-pair equilibria followed by standard Wittig reaction steps.
