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Triethylamine
Selected AbstractsAltering lipase activity and enantioselectivity in organic media using organo-soluble bases: Implication for rate-limiting proton transfer in acylation stepBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2006Chun-Chi Chen Abstract With the hydrolytic resolution of (R,S)-naproxen 2,2,2-trifluoroethyl esters via a partially purified papaya lipase (PCPL) in water-saturated isooctane as the model system, the enzyme activity, and enantioselectivty is altered by adding a variety of organo-soluble bases that act as either enzyme activators (i.e., TEA, MP, TOA, DPA, PY, and DMA) or enzyme inhibitors (i.e., PDP, DMAP, and PP). Triethylamine (TEA) is selected as the best enzyme activator as 2.24-fold increase of the initial rate for the (S)-ester is obtained when adding 120 mM of the base. By using an expanded Michaelis,Menten mechanism for the acylation step, the kinetic analysis indicates that the proton transfer for the breakdown of tetrahedral intermediates to acyl-enzyme intermediates is the rate-limiting step, or more sensitive than that for the formation of tetrahedral intermediates when the enzyme activators of different pKa are added. However, no correlation for the proton transfers in the acylation step is found when adding the bases acting as enzyme deactivators. © 2006 Wiley Periodicals, Inc. [source] ChemInform Abstract: Ring Opening of Aziridines with Tetranitromethane in the Presence of Triethylamine.CHEMINFORM, Issue 32 2010-Tosylamino Nitrates., Efficient Synthesis of Abstract Tetranitromethane is used as an oxidant and source of the nitro group. [source] ChemInform Abstract: A Convenient Synthesis of 2-Arylnaphtho[1,2-d]oxazole Derivatives Promoted by Triethylamine.CHEMINFORM, Issue 8 2008Hong Li Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Solvent-Free Synthesis of Cyanohydrin Derivatives Catalyzed by Triethylamine.CHEMINFORM, Issue 8 2006Alejandro Baeza Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF. [source] Unusual Cyclization of N-(1-Aryl-1-chloro-2,2,2-trifluoroethyl)-N,-(p-tolyl)-carbodiimines in the Presence of Triethylamine.CHEMINFORM, Issue 43 2004M. V. Vovk Abstract For Abstract see ChemInform Abstract in Full Text. [source] Development of a new method for analysis of Sudan dyes by pressurized CEC with amperometric detectionELECTROPHORESIS, Issue 11 2007Shaofeng Liu Abstract A new analytical method, pressurized CEC (pCEC) with amperometric detection (AD) using 1.5,,m RP nonporous silica packed columns has been developed for the rapid separation and determination of four Sudan dyes in hot chilli. The influence of several experimental parameters on the retention behavior has been investigated. The electrochemical oxidation of Sudans I,IV separated by pCEC can be reliably monitored with a carbon electrode at +0.95,V (vs. Ag/AgCl). Fast and efficient separation of the analytes was achieved within 7,min by pCEC under the optimum conditions with an ACN/water (95:5%) mobile phase containing formic acid (pH,4.3), 5% acetone and 0.002% triethylamine using a separation voltage of 12,kV. The detection limits for four Sudan dyes ranged from 8.0,×,10,7 to 1.2,×,10,6,mol/L. To evaluate the feasibility and reliability of this method, the proposed pCEC-AD method was further demonstrated with hot chilli samples spiked with Sudan dyes. [source] A ,3 -Alkoxo-Bridged Tetranuclear [Cu4L2] Copper(II) Complex of a Hexadentate N2O4 Donor Ligand with a [6 + 0] Cu4O4 Cubane Core: Synthesis, Crystal Structure, and Magnetic PropertiesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2010Dipankar Maity Abstract A novel hexacoordinating non-Schiff base ligand (H4L) with N2O4 donor atoms has been synthesized by simple Mannich reactions. The use of this ligand with Cu(ClO4)2·6H2O in different molar ratios as well as pH leads to the formation of a mononuclear species and a tetranuclear CuII complex possessing a cubane [Cu4L2] core with almost equal Cu···Cu separation. In the presence of an excess amount of copper(II) ions and triethylamine at reflux, the mononuclear [CuH2L] species can be converted into the tetranuclear one, whereas the reverse process was not observed even after prolonged reaction time. Both the complexes have been characterized by single-crystal X-ray diffraction and magnetic measurements. Magnetic studies reveal that complex 1 displays a paramagnetic Curie-type behavior whereas 2 displays a singlet-spin ground state induced by strong intramolecular antiferromagnetic interactions. [source] Reprogramming of a Malonic N-Heterocyclic Carbene: A Simple Backbone Modification with Dramatic Consequences on the Ligand's Donor PropertiesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2010Vincent César Abstract Reaction of N,N, -dimesitylformamidine with dimethylmalonyl dichloride in dichloromethane in the presence of an excess of triethylamine gives the 2-chloro-4,5-dioxohexahydropyrimidine 1. The corresponding diamidocarbene 3 is generated in situ by further deprotonation with KHMDS at ,40 °C and identified by trapping with S8 to give the fully characterized (including X-ray structure) sulfur adduct 4. It also reacts with [RhCl(cod)]2 to yield the NHC complex [RhCl(3)(cod)] (5) (characterized also by X-ray structure). The donor properties of 3 were evaluated against the established IR [,(CO)] scale from [RhCl(3)(CO)2] (6). The average value of ,(CO) = 2045 cm,1 indicates that the diamidocarbene 3 is much less nucleophilic than structurally relevant six-membered NHCs including the anionic diaminocarbenes previously reported in our group. [source] Synthesis and Characterization of Novel Titanium, Germanium, and Tin Silazane Complexes Bearing a Cyclohexasilazanetriido LigandEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2007Christian Lehnert Abstract Novel heterometallic silazane complexes were synthesized by the reaction of 1-lithio-2,2,4,4,6,6-hexamethylcyclotrisilazane Li(HMCTS)H2 with the tetrachloride salts of titanium and germanium as well as by the reaction of 1,1,3,3,5,5-hexamethylcyclotrisilazane H3(HMCTS) with tin tetrachloride and excess triethylamine. The products [H3(DMCHS)TiCl] (1), [H3(DMCHS)GeCl] (2), and [H3(DMCHS)SnCl] (3) {H3(DMCHS) = 2,2,4,4,6,6,8,8,10,10,12,12-dodecamethylcyclohexasilazane-1,5,9-triido} were characterized by 1H-, 13C-, 14N-, and 29Si NMR spectroscopy, elemental analyses and single-crystal X-ray structure analyses. The complexes have a surprising and interesting structure, that of a new dodecamethylcyclohexasilazane system with the Ti, Ge, or Sn atom in the center. These metal atoms are coordinated by one chlorine atom and three nitrogen atoms. The metal centers are part of three six-membered hetero-silazane rings. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Designed Assembly and Structures and Photoluminescence of a New Class of Discrete ZnII Complexes of 1H -1,10-Phenanthroline-2-oneEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2006Jie-Peng Zhang Abstract The hydrothermal reaction of 1H -1,10-phenanthroline-2-one (Hophen), zinc acetate, benzoic acid (Hba), and triethylamine (3.0 mL) yields the tetranuclear complex [Zn4(,3 -OH)2(ophen)4(ba)2] (2), which features a chair-like Zn4(,3 -OH)2 cluster with two ba ligands centrosymmetrically oriented. [(OAc){Zn3(,3 -OH)(ophen)3}(ox){Zn3(,3 -OH)(ophen)3}(OAc)] (3; ox = oxalate) was isolated when less triethylamine (1.0 mL) was used. Two Zn3(,3 -OH)(ophen)3 clusters in 3 are linked together by an oxalate to form a dumbbell-like structure in which the acetate and oxalate ligands point outward from the Zn3(,3 -OH)(ophen)3 cluster with an acute bending angle. A geometric analysis reveals that Zn3(,3 -OH)(ophen)3 and dicarboxylate with an obtuse bending angle cannot form an infinite zigzag chain, whereas the ring isomer can. With isophthalate (ipa), thiophene-2,5-dicarboxylate (tda), and 4,4,-oxybis(benzoate) (oba) instead of the acetate of 3 three new complexes, namely [{Zn3(,3 -OH)(ophen)3}(ipa)2{Zn3(,3 -OH)(ophen)3}]·0.5H2O (4), [{Zn3(,3 -OH)(ophen)3}(tda)2{Zn3(,3 -OH)(ophen)3}] (5), and [{Zn3(,3 -OH)(ophen)3}(oba)2{Zn3(,3 -OH)(ophen)3}] (6), were obtained in which two Zn3(,3 -OH)(ophen)3 clusters are linked by a pair of ipa, tda, or oba ligands to form isostructural, cluster-based 2:2 metallomacrocycles. Photoluminescence studies of 2,6 revealed that their luminescent properties are derived from ophen-based ,-,* excited states. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis, Characterization, and Properties of Some Copper(II) Complexes of 2-Pyridineformamide Thiosemicarbazone (HAm4DH)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2006María del Carmen Aguirre Abstract Reactions between different copper(II) salts and 2-pyridineformamide thiosemicarbazone (HAm4DH) in neutral ethanolic media led to the formation of complexes with the formulae [Cu(HAm4DH)X2] (X = Cl or Br) (1, 2) and [Cu(HAm4DH)2]X2 (X = NO3 or ClO4) (3, 4). The same reactions carried out in the presence of triethylamine gave rise to new complexes with the general formulae [Cu(Am4DH)X] (X = Cl, Br, AcO, or NO3) (5,8), [Cu(H2O)(Am4DH)](ClO4) (9), and [Cu(Am4DH)2] (10), many of which were isolated with different molecules of crystallization and contain a deprotonated thiosemicarbazone (Am4DH). These complexes were characterized by elemental analysis, and different spectroscopic and magnetic techniques. The thermal and redox behavior of the complexes was also evaluated. Complexes 1, 2, 5, and 6 show better nuclease activity than [Cu(phen)2]2+. Inaddition, crystals were isolated in the cases of [Cu(HAm4DH)Cl2]2 (5a), 1,[Cu(Am4DH)Cl] (5b), 1,[Cu(Am4DH)Br] (6a), and [Cu(HAm4DH)(H2O)(ClO4)2]·MeOH·H2O (9a) and these structures were analyzed by X-ray diffraction. Compound 5a has a dimeric structure with chlorine bridges and shows weak antiferromagnetism (J = ,12.2 cm,1). Complexes 5b and 6a are one-dimensional polymers formed through halogen bridges and the deprotonated thiosemicarbazone in the thiolate form. In compound 9a the copper(II) is in a distorted octahedral environment with two ClO4 units coordinated to the metal center. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis, Characterization and in Vitro Study of the Cytostatic and Antiviral Activity of New Polymeric Silver(I) Complexes with Ribbon Structures Derived from the Conjugated Heterocyclic Thioamide 2-Mercapto-3,4,5,6-tetra- hydropyrimidineEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2004Panagiotis C. Zachariadis Abstract Silver(I) bromide reacts with 2-mercapto-3,4,5,6-tetrahydropyrimidine (StpmH2, C4H8N2S) in DMSO with an excess of triethylamine to give a water-insoluble complex of formula [Ag6(,2 -Br)6(,2 -StpmH2)4(,3 -StpmH2)2]n (1), while the reaction of silver(I) nitrate with StpmH2 under the same conditions gives a water-insoluble complex of formula [{Ag4(,2 -StpmH2)6}(NO3)4]n (2). The products were characterized by elemental analyses, and FT-IR far-IR, UV/Vis, 1H and 13C NMR spectroscopy. Crystal structures of complexes 1 and 2 were determined by X-ray diffraction. Complex 1, C24H48Ag6N12S6, crystallizes in the triclinic system space group P , a = 8.041(1) Å, b = 12.838(4) Å, c = 13.281(2) Å, , = 68.40(1)°, , = 72.97(1)°, , = 87.80(2), Z = 2, forming a one-dimensional infinite ribbon structure by strong interatomic interactions of two ,2 -Br bonds with Ag(1). Complex 2, C24H48Ag4N16O12S6, crystallizes in the orthorhombic system, space group Cmc21, and a = 32.148(3) Å, b = 9.461(2) Å, c = 7.234(1) Å, , = , = , = 90°, Z = 8, forming infinite Ag,S,Ag chains which are bridged to each other by a sulfur atom of ,2 -StpmH2 ligands. Complexes 1 and 2 were studied for their cytostatic activity against murine leukemia (L1210) and human T-lymphocyte (Molt4/C8 and CEM) cells and for their antiviral activity against a wide variety of viruses. They are markedly cytostatic at 50% inhibitory concentration (IC50) values ranging from 3 to 17 ,g/mL. None of the compounds showed appreciable antiviral activity at subtoxic concentrations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis, Structure and Chemical Transformations of EthynylgermatranesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2003Edmunds Lukevics Abstract Ethynylgermatranes have been prepared from monosubstituted acetylenes by a three-step synthesis without isolation of the hydrolytically unstable intermediate chlorogermanes and ethoxygermanes. Boiling an equimolar mixture of tetrachlorogermane Cl4Ge, acetylene RC,CH and triethylamine in hexane leads to germylation of the Csp,H bond and the formation of ethynyl-substituted trichlorogermanes. Subsequent alkoxylation of chlorogermanes by ethanol in the presence of triethylamine affords triethoxygermanes that then take part in transalkoxylation with triethanolamine to give ethynylgermatranes. The molecular structures of all ethynylgermatranes and the hexacarbonyldicobalt complex of 1-heptynylgermatrane have been determined by X-ray crystallography. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Halodecarboxylation Reaction of 4-Alkylidene-,-lactamsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 26 2009Paola Galletti Abstract The synthesis of halo- and dihalovinyl-,-lactams by a halodecarboxylation reaction has been developed. Optimized procedures gave good yields of dibromo-, iodo- and diiodovinyl derivatives. The unprecedented synthesis of dihalo compounds by a Hunsdieker reaction was investigated in detail by 1H NMR analysis, which allowed the formulation of a reaction mechanism and revealed the role of triethylamine as a deiodinating agent. The dibromo- and diiodoalkylidene-,-lactams obtained were tested in a cross-coupling reaction with dimethylzinc. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Ring Expansion of 2-(,-Hydroxyalkyl)azetidines: A Synthetic Route to Functionalized PyrrolidinesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2008François Durrat Abstract A series of 2-(,-hydroxyalkyl)azetidines synthesized from enantiomerically pure ,-amino alcohols and presenting various patterns both on the four-membered ring and on the adjacent hydroxy group were treated with either thionyl chloride or methanesulfonyl chloride in the presence of triethylamine. The thus-prepared 2-(,-chloro- or ,-methanesulfonyloxyalkyl)azetidines were shown to rearrange stereospecifically into 3-(chloro- or methanesulfonyloxy)pyrrolidines. When this rearrangement is conducted in the presence of an added nucleophile (NaN3, KCN, KOH, or NaOAc), the produced pyrrolidine incorporates the added nucleophile at C-3 stereospecifically. The relative configuration of the substituents in the formed pyrrolidines is consistent with a mechanism involving the formation of an intermediate bicyclic aziridinium ion, which is opened regioselectively at the bridgehead carbon atom. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] 3-Tocopherylisoxazolines by [2+3] CycloadditionEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2004Thomas Rosenau Abstract New isoxazoline derivatives of ,-tocopherol (1), the main component of vitamin E, were synthesized in a facile, two-step sequence consisting of nitration followed by 1,3-dipolar cycloaddition. 5-Nitromethyl-,-tocopheryl acetate (3), obtained from the cheap ,-tocopheryl acetate (2) by direct nitration in one step, acted as the nitrile oxide precursor in the reaction with various alkenes. The facile conversion proceeded in the presence of equimolar amounts of PhNCO and catalytic amounts of triethylamine. The NMR spectra of the product isoxazolines 5,13, showing strongly temperature-dependent resonances of the 4,,-CH, 4-CH2 and the acetyl group, are discussed, and the crystal structures of model compounds containing a methyl group instead of the isoprenoid side chain are presented. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Palladium-Catalyzed Preparation of Propargylic or Allenylic Sulfides from Propargyl Halides or Mesylate and ThiolsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2004Ken Tsutsumi Abstract In the presence of a catalytic amount of Pd0 -dppe complex [dppe: 1,2-bis(diphenylphosphanyl)ethane], generated in situ from [Pd2(dba)3·CHCl3] and dppe, propargylic bromide 1a reacted with an equimolar amount of propanethiol at 60 °C in DMF to afford propargylic sulfide 2 in an excellent yield. The reaction occurs readily when carried out in the presence of the weak base triethylamine. The choice of both the phosphane, which is employed as the palladium atom's ligand, and the solvent have a remarkable effect on this reaction. We found that the optimum conditions for the reaction are those using a bidentate phosphane ligand (dppe) in a polar solvent (DMF). Compound 1a reacted smoothly with both aromatic (PhSH) and secondary thiols (CySH) in high yields. The reactions with thiols bearing functional groups (OH or Cl) proceeded selectively in good to moderate yields. Primary chlorides 1b,e were readily converted into their corresponding propargylic sulfides 7,10 in high yields. The Pd0 -dppe catalyst was ineffective in the reaction of the bromide 1g bearing a tBu group at the propargylic position, but the reaction of the corresponding mesylate 1h using the Pd0 -DIOP catalyst [DIOP = O -isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphanyl)butane] at 100 °C afforded the product 11 in good yield. Allenylic sulfides were obtained from 1g,i. We suggest that a cationic ,3 -type complex may be a more reactive intermediate in this catalytic reaction than neutral ,1 - or ,3 -allenyl/propargylpalladium complexes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Phosphorylation of derivatives of ,-dialkyaminocrotonitriles with phosphorus(III) halidesHETEROATOM CHEMISTRY, Issue 4 2009Aleksandr N. Kostyuk The reaction of ,-dialkylaminocrotontriles with phosphorus(III) halides has been investigated. The basicity of the dialkylamino group influences the phosphorylation markedly, with pyrrolidine being the amine of choice. It was found that a solvent and the ratio of triethylamine play a significant role in phosphorylation. Although chloro- and dichlorophosphine derivatives proved impossible to separate as individual compounds; their solutions can be successfully used for further transformations. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:194,201, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20532 [source] Chalcogenation reactions of a stable ferrocenyldiphosphene: Formation of thia-, selena-, and telluradiphosphiranes,HETEROATOM CHEMISTRY, Issue 5 2008Noriyoshi Nagahora The reactions of TbtPPTbt (Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl) with elemental sulfur and selenium in the presence of triethylamine resulted in the formation of the corresponding thia- and selenadiphosphiranes in 71% and 65%, respectively, whereas the tellurization reaction was unsuccessful probably due to the steric reason. On the other hand, treatment of TbtPPFc (Fc = ferrocenyl) with elemental sulfur, selenium, and tributylphosphine telluride afforded the corresponding thia-, selena-, and telluradiphosphiranes in 84%, 88%, and 66% yields, respectively. The molecular structures of these three-membered heterocyclic compounds were confirmed by spectroscopic analysis. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:443,449, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20449 [source] New bis(diphenylphosphino)aniline derivatives: Synthesis and spectroscopic characterizationHETEROATOM CHEMISTRY, Issue 6 2007Nermin Biricik Six new multidentate bis(diphenyl-phosphino)amine [R,N(PPh2)2] ligands have been prepared from the reaction of aniline derivatives, R,NH2, with Ph2PCl in the presence of triethylamine. All of the compounds were obtained in good yields and were characterized by NMR, IR, and microanalysis. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:613,616, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20362 [source] Indolizines, triazolo[4,3- a]pyridines, benzimidazo[1,2- d]oxadiazoles, and pyrazolo[1,5- c]triazoles via nitrogen and sulfur ylidesHETEROATOM CHEMISTRY, Issue 6 2004Kamal M. Dawood The pyridinium salts 2a,b reacted with dimethyl acetylenedicarboxylate (DMAD) to give the indolizine derivatives 6a,b. Pyridinium salts 2a,b also reacted with pyrazole-5-diazonium salt to afford the hydrazonoyl bromides 8a,b, which on treatment with aqueous ethanolic sodium carbonate furnished the 8aH -1,2,4-triazolo[4,3- a]pyridine 10. When sulfonium bromide 11 was treated with nitrous acid and with pyrazole-5-diazonium salt, it afforded the new hydroximoyl and hydrazonoyl halides 12 and 17, respectively. Compound 12 reacted with 2-methylthiobenzimidazole to furnish benzimidazo[1,2- d]-1,2,4-oxadiazole derivative 14. Treatment of either 12 with 3-phenyl-5-aminopyrazole or 17 with triethylamine resulted in the formation of the same product: pyrazolo[1,5- c]-1,2,4-triazole derivative 16. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:432,436, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20037 [source] Structures and properties of two diastereomeric cyclic sulfites derived from cis -3,4-di- tert -butylthiolane-3,4-diol and thionyl chlorideHETEROATOM CHEMISTRY, Issue 7 2003Sanae Tanaka cis-3,4-Di-tert-butylthiolane-3,4-diol (1) was treated with an equimolar amount of thionyl chloride in the presence of triethylamine or pyridine in several solvents of different polarity to furnish two diastereomeric sulfites 2a and 2b generally in excellent combined yields. Although 2a was consistently formed as the major diastereomer when pyridine was used as the base, 2a and 2b were formed in approximately equal amounts when triethylamine was used as the base in polar solvents. X-ray crystallographic analyses revealed that the SO group of 2a is anti to the thiolane ring and that of 2b syn to the thiolane ring. Density functional theory calculations (B3LYP/6-31G* level) revealed that 2a is less stable than 2b by 1.28 kcal mol,1, although 2a was formed generally as the predominant diastereomer. Spectroscopic data of 2a and 2b are discussed with emphasis on comparison with those obtained by calculations. Treatment of 2a and 2b with m-chloroperbenzoic acid resulted in the oxidation of the divalent sulfur atom of the thiolane ring and not the sulfite sulfur atom. The above oxidations took place exclusively at the syn-side with respect to the tert-butyl groups.© 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:587,595, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10192 [source] Pyrimidin-/thiazol-/thiazolin-ylidenamidothiophosphoric dichloridesHETEROATOM CHEMISTRY, Issue 6 2003Vijaya Kabra Nine new amidodichlorothiophosphorus(V) derivatives incorporating pyrimidine, thiazole, and thiazoline rings were obtained by sulfurization of the corresponding aminodichlorophosphines generated in situ from the reaction of the respective N-alkyl-2-aminocycloiminium halide with PCl3 in the presence of triethylamine. These pyrimidin-/thiazol-/thiazolin-ylidenamidothiophosphoric dichlorides were isolated as stable crystalline solids and are well characterized by elemental analysis, NMR, and mass spectroscopy. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:498,502, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10170 [source] Stereospecific synthesis of azeto[2,1- d]- [1,5]benzothiazepin/diazepin-1-onesHETEROATOM CHEMISTRY, Issue 6 2003Xu Huang 2a,4-Disubstituted 2-phenoxy-2,2a,3,4-tetrahydro-1H-azeto[2,1-d][1,5]benzothiazepin-1-ones and 5-benzoyl-2-phenoxy-2a,3,4,5-tetrahydro-azeto[1, 2-a][1,5]benzodiazepin-1(2H)-ones were synthesized in moderate to good yields by stereospecific Staudinger cycloaddition reactions of 2,4-disubstituted 2,3-dihydro-1,5-benzothiazepines and 1-benzoyl-2,3-dihydro-1H-1,5-benzodiazepines, respectively, with phenoxy acetyl chloride in the presence of triethylamine in anhydrous benzene. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:564,569, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10196 [source] 5-Chloro-3-methylthio-1,2,4-thiadiazol-2-ium chlorides as useful synthetic precursors to a variety of 6a,4 -thiapentalene systemsHETEROATOM CHEMISTRY, Issue 1 2003Georges Morel Title salts 3 were easily obtained by treatment of formimidoyl isothiocyanates 1 with a twofold excess of methanesulfenyl chloride. They showed interesting chemical behavior toward several nitrogen and carbon nucleophiles. Substitution reactions with isothioureas and acetamide in the presence of triethylamine gave the 1H, 6H -6a,4 -thia-1,3,4,6-tetraazapentalenes 7 and 6H -6a,4 -thia-1-oxa-3,4,6-triazapentalene 9, respectively. Addition of p -toluidine furnished the 5-imino-thiadiazole derivatives 10, which reacted further with diverse heterocumulenes to yield the corresponding thiatriaza- and tetraazapentalene species 11. The N,N,-bis(1,2,4-thiadiazol-5-ylidene)diaminobenzenes 13 were also prepared and reacted with phenyl isothiocyanate. Two stable rotational isomers were separated for the 1,2-phenylene product 14b. Other ,-hypervalent sulfur compounds 16 were synthesized under similar conditions from salts 3 and methyl cyanoacetate or dimethyl malonate. The structural assignments were discussed on the basis of IR and NMR spectroscopic data and received additional support from X-ray analysis of substrate 16a. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:95,105, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10106 [source] Synthesis of 1,3,3a,5-tetraaryl-3a,4,5,6-tetrahydro-3H -1,2,4-triazolo[4,3- a] [1,5]benzodiazepinesHETEROATOM CHEMISTRY, Issue 6 2001Jiaxi Xu A series of 3a,5-diaryl-1,3-diphenyl-3a,4,5,6-tetrahydro-3H-1,2,4-triazolo[4,3-a][1,5]benzo-diazepines was synthesized by the cycloaddition reactions of 2,4-diaryl-2,3-dihydro-1H-1,5-benzo-diazepines and N-phenylbenzonitrileimine generated from N-phenylbenzenecarbohydrazonic chloride in the presence of triethylamine in anhydrous tetrahydrofuran. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:557,559, 2001 [source] Kinetic investigation on the reactions of p -toluenesulfonyl chloride with p -substituted benzoic acid(s) in the presence of triethylamine in aprotic solventsINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 5 2009Subbiah Ananthalakshmi Second-order rate constants of the reactions of p -toluenesulfonyl chloride with p -substituted benzoic acids in the presence of triethylamine in acetonitrile/acetone under equimolar and pseudo-first-order conditions have been determined by the conductometric method using the Guggenheim principle at 25, 30, 35, and 40°C. The reactions follow second order with respect to the whole and first order with respect to each of the reactants. The order of reactivity of the substituents in benzoic acid is rationalized. Activation parameters are obtained by applying the usual methods. The Hammett plot has been found nonlinear, whereas the Bronsted plot shows good correlation. This may be explained on the basis of electronic effects of substituents on the reaction center. Kinetic data and the product analyses indicate that the reaction proceeds through direct nucleophilic attack on the sulfur center. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 303,308, 2009 [source] On the Trapping of Vinylgold IntermediatesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010A. Stephen Abstract An internal aryl-substituted ortho -alkynylphenol and a similar aniline with stoichiometric amounts of N,N, -bis(2,6-diisopropylphenyl)imidazol-2-ylidene-gold tosylate [(IPr)AuOTs] and triethylamine gave the aurated heterocycles as stable intermediates of the corresponding gold(I)-catalysed hydrooxylation and hydroamination reactions. X-ray crystal structure analyses of both products could be obtained. A similar internal alkyl-substituted ortho -alkynylphenol gave only the cycloisomerised product, no aurated intermediate could be detected. [source] Substitution- and Elimination-Free Phosphorylation of Functionalized Alcohols Catalyzed by Oxidomolybdenum TetrachlorideADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010Cheng-Yuan Liu Abstract Among 14 oxidometallic species examined for catalytic phosphorylation of the tested alcohols, oxidomolybdenum tetrachloride (MoOCl4) was found to be the most efficient with a negligible background reaction mediated by triethylamine (Et3N). The new catalytic protocol can be applied to the chemoselective phosphorylations of primary, secondary and tertiary alcohols as well as the substitution-free phosphorylations of allylic, propargylic, and benzylic alcohols. Functionalized alcohols bearing acetonide, tetrahydropyranyl ether, tert -butyldimethylsilyl ether, or ester group are also amenable to the new catalytic protocol. The most difficult scenarios involve substitution-free phosphorylations of 1-phenylethanol and 1-(2-naphthyl)ethanol which can be effected in 95 and 90% yields, respectively. ESI-MS, IR, 1H, and 31P,NMR spectroscopic analyses of the reaction progress suggest the intermediacy of an alkoxyoxidomolybdenum trichloride-triethylamine adduct such as [(RO)Mo(O)Cl3 -Et3N] to be responsible for the catalytic turnover. [source] 3,5-Bis(n -perfluorooctyl)benzyltriethylammonium Bromide (F-TEBA): An Efficient, Easily Recoverable Fluorous Catalyst for Solid-Liquid PTC ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Gianluca Pozzi Abstract A readily available 3,5-bis(perfluorooctyl)benzyl bromide and triethylamine were reacted under mild conditions to give 3,5-bis(n -perfluorooctyl)benzyltriethylammonium bromide (F-TEBA), an analogue of the versatile phase-transfer catalyst, benzyltriethylammonium chloride (TEBA), containing two fluorous ponytails. This perfluoroalkylated quaternary ammonium salt was successfully employed as a catalyst in a variety of reactions run under solid-liquid phase-transfer catalysis (SL-PTC) conditions. Thus, being both hydrophobic and lipophobic, F-TEBA could be quickly recovered in quantitative yields, and reused without loss of activity over several reaction cycles. [source] | |||||||||||||||||||||||||||||||||||||