- Synthesis and characterization of lithiated dendrimers
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The synthesis of the precursor phenylthiomethyl-functionalized carbosilane dendrimers Si[(CH2)3SiMe2CH2SPh]4 (1) and Si{(CH2)3Si[(CH2)3SiMe2 CH2SPh]3}4 (2) is described. Reacting 1 and 2 with lithium naphthalenide gives the first lithiomethyl-functionalized dendrimers Si[(CH2)3SiMe2CH2Li]4 (7) and Si{(CH2)3Si[(CH2)3 SiMe2CH2Li]3}4 (11). Deutero, trimethylsilyl, trimethylstannyl, and tri-n-butylstannyl derivatives of these dendrimers, as well as a method to enable isolation of the lithiated dendrimers as solids, are described.
- Meijboom, Reinout,Hutton, Alan T.,Moss, John R.
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- Tin-magnesium transmetallation reactions
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Sulfur-functionalized methyltin compounds nBu3SnCH2S(O)iR (i = 0, 1, 2; R = Me, Ph) underwent transmetallation with Grignard compounds MgR′X (R′ = Me, nBu, Ph; X = Cl, Br, I) and diorganomagnesium compounds MgR′R″ (R′/R″ =
- Yousef, Rushdi I,Rüffer, Tobias,Schmidt, Harry,Steinborn, Dirk
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- Continuous organomagnesium synthesis of organometallic compounds
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Continuous organomagnesium synthesis of a number of organic derivatives of 14th group elements of the periodic table was examined in a column apparatus with an agitator. An effect of a molar ratio of reactants, temperature in a reaction zone, and other factors was studied on the yield and composition of the products.
- Storozhenko,Grachev,Klochkov,Shiryaev
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- CATHODIC SYNTHESIS OF TETRAALKYLTIN COMPOUNDS.
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Methyl bromide and allyl bromide are efficiently reduced at a tin electrode to form tetramethyl and tetraallyl tin. A variety of other bromides with appreciably more negative reduction potentials also produce tetra-substituted tin compounds but the yields are lower. At higher potentials, cathode disintegration is a consequence of the competitive reduction of the carrier electrolyte (Et//4N** plus Br**-).
- Ulery
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- Mechanism of the reaction of tri-n-butylstannyl anion with n-butyl bromide and iodide as studied by the 119Sn CIDNP technique
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The mechanism of the reaction of the tri-n-butylstannyl anion with n-butyl bromide and iodide in THF was studied by the chemically induced dynamic nuclear polarization (CIDNP) technique. Strong 119Sn CIDNP spectra were observed for the first ti
- Wakasa, Masanobu,Kugita, Tsuyoshi
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- ELECTROSYNTHESIS OF DIALKYLTIN DERIVATIVES
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Reduction of alkyl halides at a Sn cathode in TEAX/MeCN results in mixed degrees of alkylation of this metal. Primary products include RSn, R//2Sn, and/or reactive polytins containing these units. Final products depend on environment and tend to be complicated mixtures. A direct synthesis with good yields of dibutyltin oxide and dioctyltin oxide results from aerating the catholyte. A mixture of alkyltin halides is formed in an undivided cell by the interaction of anode and cathode products; other products include the tetraethylammonium alkylhalostannates. Factors governing the course of cathodic alkylation are discussed.
- Ulery
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- The interaction of organotin(IV) acceptors with 1,4-bis(5-hydroxy-1-phenyl-3-methyl-1H-pyrazol-4-yl)butane-1,4-dione
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From the interaction of organotin(IV) halides SnR2Cl2 with 1,4-bis(5-hydroxy-1-phenyl-3-methyl-1H-pyrazol-4-yl)-butane-1,4-dione (Q2QH2) in methanol in the presence of base the complexes [SnR2(Q2Q)] (1: R = isob
- Pettinari, Claudio,Marchetti, Fabio,Pettinari, Riccardo,Cingolani, Augusto,Drozdov, Andrei,Troyanov, Sergei
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- Synthetic Route to 1,1′,2,2′-Tetraiodoferrocene That Avoids Isomerization and the Electrochemistry of Some Tetrahaloferrocenes
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An efficient synthesis of 1,1′,2,2′-Tetraiodoferrocene is described that uses 1,1′,2,2′-Tetrakis(tri-n-butylstannyl)ferrocene as a key intermediate in its synthesis. In an attempt to examine the stepwise mechanism, the reaction of the tetratin-substituted ferrocene 1,1′,2,2′-Tetrakis(tri-n-butylstannyl)ferrocene with iodine was monitored by 1H NMR and a series of coexisting intermediate compounds such as 1,1′-bis(tri-n-butylstannyl)-2,2′-diodoferrocene were observed. The crystal structure of 1,1′,2,2′-Tetraiodoferrocene has been determined, and it is compared with the structure of the previously reported 1,1′,2,2′-Tetrabromoferrocene and 1,2,4,1′-Tetraiodoferrocene. The comparative electrochemistry of 1,1′,2,2′-Tetrachloroferrocene, 1,1′,2,2′-Tetrabromoferrocene, and 1,1′,2,2′-Tetraiodoferrocene is described. The crystal structure of 1,2,1′-Triiodoferrocene is also reported for comparative use to illustrate the scope of the synthetic method.
- Butler, Ian R.,Coles, Simon J.,Corsini, Maddalena,De Biani, Fabrizia Fabrizi,Evans, Daniel M.,Horton, Peter N.,Hughes, David D.,Murphy, Patrick J.
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- Synthesis of 3-stannyl and 3-silyl propargyl phosphanes and the formation of a phosphinoallene
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The group 14 chloropropargyls R3ECCCH2Cl (R3E = nBu3Sn, Ph3Sn, Me2PhSi, iPr3Si, nPr3Si, nBu3Si), obtained by a modified literature procedure, react with LiPPh2 to afford the novel propargyl phosphanes Ph2PCH2CCER3 in high yield, as viscous oils; (Me3Si)2PCH2CCSiPhMe2 is similarly obtained from LiP(SiMe3)2. In contrast, the reaction of PhCCCH2MgCl with ClP(NEt2)2 fails to produce a comparable propargyl phosphane, but generates preferentially (>70%) the novel phosphinoallene (Et2N)2PC(Ph)CCH2, which is characterised spectroscopically, and through its reaction with HCl. The coordination chemistry of representative phosphanes is explored with respect to platinum and palladium for the first time.
- Saunders, Amy J.,Crossley, Ian R.
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- Triorganotin(IV) derivatives of several 4-acyl-5-pyrazolonato ligands: Synthesis, spectroscopic characterization and behavior in solution crystal structure of aquotrimethyl(4-p-methoxybenzoyl-1-phenyl-3-methyl-pyrazolon-5-ato)tin(IV)
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New triorganotin(IV) derivatives [(Q)SnR3 · x(H2O)] (x = 0, R = Ph; x = 1, R = Me and nBu) (in general QH = 1-R′-3-methyl-4-R″ (C=O)-pyrazol-5-one; in detail Q′H: R′ = C6H5, R″ = C6H5; QAH: R′ = C6H5, R″ = p-CH3O-C6H4; QNH: R′ = C6H5, R″ = p-NO2-C6H4; QBrH: R′ = C6H5, R″ = p-Br-C6H4; Q″ H: R′ = C6H5, R″ = CH3; QClH: R′ = C6H5, R″ = CCl3; QFH: R′ = C6H5, R″ = CF3; QMH: R′ = CH3, R″ = C6H5; QDH: R′ = CH3, R″ = CH3) have been synthesized and characterized by analysis and spectral (IR and 1H, 13C and 119Sn NMR) data. The (Q)SnPh3 derivatives are five-coordinated in the solid state, with a likely skewed cis-trigonal bipyramidal (cis-TBP) geometry around the tin center and the ligand (Q)- acting in the bidentate form. In [(Q)SnR3 · (H2O)] derivatives (R = nBu or Me) a coordination site is occupied by water, with the ligand (Q)- coordinating in a monodentate fashion. The crystal structure of [(QA)SnMe3 · (H2O)] has been determined: the tin atom is found in a distorted TBP environment, with the methyls in the equatorial positions. Two of the Sn-C bond lengths are normal (2.11(1) and 2.08(2) A) whereas the third is longer (2.18(2) A); the ligand binds the metal atom through one carbonyl oxygen in the apical position (Sn-O = 2.10(1) A). The bond length between H2O and Sn is longer (2.41(2) A), and the O-Sn-O angle is 174.9(5)°. H atoms of water are involved in an intermolecular H-bond network with uncoordinated carbonyl and the pyridinic N atom of the ligand. In chloroform solution the [(Q)SnR3 · (H2O)] derivatives (R = Me or nBu) lost the molecule of water and adopt a tetrahedral arrangement. They also give rise to a slow disproportionation, yielding SnR4 and [(Q)2SnR2] derivatives.
- Marchetti, Fabio,Pettinari, Claudio,Cingolani, Augusto,Lobbia, Giancarlo Gioia,Cassetta, Alberto,Barba, Luisa
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- THE USE OF ORGANOSODIUM INTERMEDIATES IN THE SYNTHESIS OF ALKYLTIN CHLORIDES
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The synthesis of various RxSnCl4-x compounds (R=butyl, octyl, dodecyl) from reaction between tin(IV) chloride, or a dialkyltin dichloride, and alkylsodium compounds RNa was investigated.Optimum conditions were established and some competing side-reactions identified.
- Owen, David W.,Poller, Robert C.
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- A NEW ROUTE TO TETRAORGANOTIN COMPOUNDS
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A new direct synthesis suitable for the preparation of straight-chain tetraalkyltins is described.
- Nicholson, John W.,Douek, Josephine A.,Collins, John D.
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- Can mono- or di-butyltin chlorides produce tributyltin chloride at elevated temperatures? Implications for applications in chemical vapour deposition
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The thermolysis of the butyltin chlorides at 200-300 °C in the liquid phase has been investigated by 1H, 13C, and 119Sn NMR spectroscopy. The stabilities follow the order: Bu2SnCl2 > Bu3SnC
- Davies, Alwyn G.,Sella, Andrea,Sivasubramaniam, Rajaveen
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- The effect of CO on the reaction of (tributyltin)lithium with alkyl and aryl bromides
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The reaction of (tributyltin)lithium with alkyl and aryl bromides in THF was studied in the presence of CO and of p-dinitrobenzene under several reaction conditions. The observed results indicate that electron transfer is involved in the substitution reac
- Nudelman, N. Sbarbati,Carro, Cecilia
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- Tetrabutyl tin preparation method
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The invention discloses a tetrabutyl tin preparation method. The preparation method comprises the following steps: adding magnesium powder and an ether solvent into a reactor with a stirring and refluxing device, starting to stir and heat till refluxing; then adding a small quantity of chlorobutane and a YF-017 catalyst, slowly adding a mixed solution of chlorobutane and anhydrous tin tetrachloride dropwise, conducting a refluxing reaction to the end after finishing adding; cooling to the normal temperature, adding hydrochloric acid while stirring, then allowing standing still for layering; releasing an aqueous phase on the lower layer, distilling an organic phase at the normal pressure, changing to perform reduced pressure distillation after the solvent is completely distilled, and collecting a fraction of 148-150 DEG C under the condition of the vacuum degree of minus 650 Pa, to obtain tetrabutyl tin. A small quantity of catalyst is added into a one-step reaction device, the Grignardreaction is started immediately, the heat produced in the Grignard reaction in the first step is rapidly absorbed by the alkylation reaction in the second step. Therefore, the phenomenon of materialspraying of the reaction is avoided, and safety in the industrial production is guaranteed.
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Paragraph 0013; 0014; 0016; 0018
(2018/08/04)
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- Preparation method of dibutyltin oxide
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The invention provides a preparation method of dibutyltin oxide. The dibutyltin oxide is at least prepared by (1), synthesis of tetrabutyl tin; (2), synthesis of dibutyl stannous chloride; (3), synthesis of dibutyltin oxide, wherein catalyst used in step (2) is composite of modified nano-crystalline cellulose and aluminium chloride. The dibutyltin oxide is applied to electric paint and electrophoretic paint fields.
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Paragraph 0069; 0071; 0083-0103; 0110-0130; 0137-0148
(2017/09/05)
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- IR Spectra of n-Bu4M (M = Si, Ge, Sn, Pb), n-BuAuPPh3-d15, and "n-Bu" on a Gold Surface
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Observed and DFT-calculated IR spectra of n-Bu4M (M = Si, Ge, Sn, Pb), (CH3CH2CH213CD2)4Sn, and n-BuAuPPh3-d15 are reported and assigned. The asymmetric CH stretching vibration of the CH2 group adjacent to the metal atom appears as a distinct shoulder at ~2934 cm-1, whereas for other CH2 groups it is located at ~2922 cm-1. The characteristic peak at ~2899 cm-1 is attributed to an overtone of a symmetric CH2 bend at ~1445 cm-1. In n-BuAuPPh3-d15, the CH stretching vibrations of the butyl group are shifted to lower frequencies by ~10 cm-1, and two possible rationalizations are offered.
- Kaleta, Ji?í,Bednárová, Lucie,?í?ková, Martina,Wen, Jin,Kaletová, Eva,Michl, Josef
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p. 4619 - 4625
(2017/07/11)
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- Stille coupling of an aziridinyl stannatrane
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An aziridinyl stannatrane 8 couples with aryl or alkenyl halides RX under modified Stille conditions to afford substituted aziridines. Efficient coupling at room temperature is possible in the best examples in the presence of ( tBu3P
- Theddu, Naresh,Vedejs, Edwin
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p. 5061 - 5066
(2013/07/05)
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- A redox asymmetric, cyclometalated ruthenium dimer: Toward upconversion dyes in dye-sensitized TiO2 solar cells
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We have prepared the dinuclear ruthenium complexes [(R3-tpy) Ru(N^C^N-tpy)Ru(tpy)]3+ (R = H ([5a]3+), CO2Me ([6a]3+), N^C(H)^N-tpy = 4′-(3,5-dipyridylphenyl)-2,2′: 6′,2″-terpyridine, tpy = 2,2′:6′,2″-terpyridine) and [(R3-tpy)Ru(N′^C^N′-tpy)Ru(tpy)]3+ (R = H ([5b]3+), CO2Me ([6b]3+), N′^C(H) ^N′-tpy = 4′-(3,5-di(4-tert-butylpyridyl)phenyl)-2,2′: 6′,2″-terpyridine) in a stepwise manner. The directional nature of the bridging ligand, which is potentially cyclometalating on one side, induces large redox asymmetry in the resulting dinuclear complexes. One-electron oxidation gives rise to a strong metal-to-metal charge transfer transition from the [Ru(tpy2)]2+ moiety to the cycloruthenated group, centered at 1034 nm for [6b]4+. The localized nature of the oxidation processes, the shape of the NIR band, and TD-DFT calculations allow assignment of these systems to localized Robin-Day class II. Exclusive substitution of the terminal tpy ligand on the cyclometalated ruthenium with acid moieties allows selective attachment of the dye to a semiconductor surface, whereby a possible two-step upconversion path is created in dye-sensitized solar cells for the utilization of low-energy photons.
- Wadman, Sipke H.,Van Leeuwen,Havenith, Remco W. A.,Van Klink, Gerard P. M.,Van Koten, Gerard
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p. 5635 - 5645
(2011/01/03)
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- Diorganostannide dianions (R2Sn2-) as reaction intermediates revisited: In situ 119Sn NMR studies in liquid ammonia
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It has frequently been proposed that diorganostannide dianions, SnR 22-, form during reactions of dihalodiorganostannanes or dihydrodiorganostannanes with sodium in liquid ammonia. The formation of this intermediate has been advanced to be an important step in the synthesis of a wide range of organostannanes. Here we report 119Sn NMR investigations in liquid NH3 of reaction intermediates that formed in situ during the conversions of dichlorodiphenylstannane, dihydrodiphenylstannane (diphenylstannane), dideuterodiphenylstannane, and dichlorodibutylstannane, respectively. This study revealed that the proposed SnR22- dianion was not present, but tetraorganodistannides, (R2Sn-SnR2)2-, and hydrodiorganostannides (tin hydrides), R2SnH- (or R 2SnD-, respectively), were detected instead.
- Trummer, Markus,Caseri, Walter
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p. 3862 - 3867
(2010/12/24)
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- Aminostannanes and aminostannylenes containing a C,N-chelated ligand
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Aminotin(II and IV) compounds {[(2,6-i-Pr-C6H 3)(H)N]-μ-(Sn)-Cl}2, {2-[(CH3) 2NCH2]C6H4}2Sn[N(H)(2,6- i-Pr-C6H3)]2 and {2-[(CH3) 2NCH2]C6H4}Sn[N(2,6-i-Pr-C 6H3)(SiMe3)] were prepared by lithium halide elimination from tin halides and corresponding lithium complexes. [(2,6-i-Pr-C6H3)(H)N]Li (1) reacts with one half of molar equivalent of SnCl2 to give {[(2,6-i-Pr-C6H 3)(H)N]-μ-(Sn)-Cl}2. The same lithium amide (1) gave with R3SnCl corresponding aminostannanes. Further reactions of these compounds with n-butyllithium gave the starting 1 and tetraorganostannanes. {2-[(CH3)2NCH2]C6H4} 2SnBr2 reacts with two equivalents of 1 to {2-[(CH 3)2NCH2]C6H4} 2Sn[N(H)(2,6-i-Pr-C6H3)]2. The dimeric heteroleptic stannylene {[(2,6-i-Pr-C6H3) (SiMe3)N](μ2-Cl)Sn}2 reacts with 2-[(CH 3)2NCH2]C6H4Li to the monomeric {2-[(CH3)2NCH2]C6H 4}Sn[N(2,6-i-Pr-C6H3)(SiMe3)]. The structure in the solid state and in solution and reactivity of products is also discussed. The unique decatin cluster has been isolated by hydrolysis of {[(2,6-i-Pr-C6H3)(H)N]-μ-(Sn)-Cl}2. The structure of some compounds was also evaluated by theoretical DFT methods.
- Padělková, Zdeňka,Havlík, Ale?,?vec, Petr,Nechaev, Mikhail S.,R??i?ka, Ale?
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p. 2651 - 2657
(2010/11/18)
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- Lithiated dimethylaminomethyl ferrocenes and ruthenocenes
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Dimethylaminomethylferrocenyl lithium and -ruthenocenyl lithium were generated using tin/lithium exchange reactions. The four different metallocenyl lithium compounds were analysed using NMR spectroscopy. The metallocenyl lithium reagents are useful reage
- Meijboom, Reinout,Beagley, Paul,Moss, John R.,Roodt, Andreas
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p. 916 - 920
(2007/10/03)
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- Wurtz-type reductive coupling reaction of primary alkyl iodides and haloorganotins in cosolvent/H2O(NH4Cl)/Zn media as a route to mixed alkylstannanes and hexaalkyldistannanes
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Mixed tetra-alkylstannanes R3SnR′ (R = Et, n-Pr, n-Bu and R′= Me, Et, n-Pr, n-Bu, n-Pent) and R2SnR′2 (R = n-Bu and R′ = Me, Et, n-Pr, n-Bu) can be easily prepared in a one-pot synthesis via coupling reaction of alkyl iodides R′I with R3SnX (X = Cl, I) and R2SnCl2 compounds in cosolvent-H2O(NH4Cl) medium mediated by zinc dust. Coupling also occurs with (Bu3Sn)2O. It has been verified that reactions are possible only with primary alkyl iodides; with secondary alkyl iodides the coupling reaction fails. When alkyl chlorides and bromides are used ditin compounds are obtained instead of the unsymmetrical tetra-alkylstannanes. This represents a route to hexaalkyldistannanes.
- Marton, Daniele,Tari, Massimo
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- Intracluster transmetalation of cuprates with stannanes
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Alkylarylcuprates with intramolecularly tethered stannanes undergo an intracluster Cu(I)/Sn(IV) transmetalation to yield arylstannanes.
- Mateo, Cristina,Cardenas, Diego J.,Martin-Matute, Belen,Echavarren, Antonio M.
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p. 2205 - 2206
(2007/10/03)
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- Preparation of benzylstannanes by zinc-mediated coupling of benzyl bromides with organotin derivatives. Physicochemical characterization and crystal structures
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Benzyltrialkyl- (1-13) and benzyltriphenylstannanes (16-22) have been easily prepared in a one-pot synthesis via coupling reaction of benzyl bromide derivatives (C6H5CH2Br and XYC6H3CH2Br, X = H, Y = o-, m-, p-CH3, o-, m-, p-F, o-, m-Cl, and p-Br; X = o-F, Y = p-Br) with R3SnCl compounds (R = Et, Pr, Bu, and Ph) in THF/H2O (NH4Cl) medium mediated by zinc powder. Such coupling also occurs with (Bu3Sn)2O. Dibenzyldibutylstannane (15) is prepared by reaction of benzyl bromide with Bu2SnCl2 or (Bu2SnCl)2O, and (2-naphthylmethyl)tributylstannane (14) by reaction of 2-(bromomethyl)naphthalene with Bu3SnCl. 13C-and 119Sn-NMR data are reported for all compounds, and M?ssbauer data for benzyltributylstannanes 10 and 11 and benzyltriphenylstannanes 16-18 and 20-22. The crystal structures of Ph3SnBn, with Bn = o- (17) and m-ClC6H4CH2 (18) and o- (20) and m-FC6H4-CH2 (21) have been determined.
- Marton, Daniele,Russo, Umberto,Stivanello, Diego,Tagliavini, Giuseppe,Ganis, Paolo,Valle, Giovanni Carlo
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p. 1645 - 1650
(2008/10/08)
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- Synthesis of analogues of monic acids A and C: Potential herbicides and inhibitors of isoleucyl tRNA synthetase
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The m-substituted benzene compounds 16-21 and biphenyl derivatives 25-27 have been synthesised as simplified analogues of monic acids A 3 and C 4. In addition the disubstituted 1,3-dioxanes 41-43 have been prepared and all compounds tested as herbicides and for their ability to inhibit spinach chloroplast isoleucyl tRNA synthetase.
- Clinch, Keith
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p. 467 - 472
(2007/10/03)
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- Perfluoroalkyl terminated urethane lubricants
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This invention relates to perfluoroalkyl group terminated urethanes, thiourethanes and ureas of the general formula where m is 1, 2 or 3, R is Rf -E and optionally R1 with the proviso that at least one R is Rf -E, Rf is a perfluoroalkyl group, R1 is a hydrocarbon group, E is a divalent linking group, X is --O--, --S--, --NR2 -- and R2 is H or lower alkyl and A is Rf E or R1 if m is 1 and a divalent or trivalent linking group if m is 2 or 3 respectively. Compounds of this general formula are useful as solid lubricants or as additives for waxes and resins providing lubricating properties.
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- Synthesis and properties of (aminomethyl)nickel complexes. [{Li(OEt2)}2Ni(CH2NC5H 10)4]: The first structurally characterized homoleptic aminomethyl complex of a transition metal
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Bu3SnCH2NR2 (R2N = Me2N, C5H10N, Ph2N) react with BuLi to give R2NCH2Li·xthf (1a, R2N = Me2N, x = 0; 1b, R2N = C5H10N, x = 0; 1c, R2N = Ph2N, x = 1). 1a and 1b react with nickel halide-phosphine adducts to give very air-sensitive homoleptic aminomethyl complexes of nickel [{Li(OEt2)}2Ni(CH2NR2)4] (2a, R2N = Me2N; 2b, R2N = C5H10N), which have been characterized analytically and spectroscopically by NMR. 2 is diamagnetic, is thermally very stable [Tdec 90-115°C (2a), 95-110°C (2b)], and reacts with water and alcohols to give R2NMe. The crystal structure of 2b (space group P21/c; R = 0.0656) exhibits a molecular Ci symmetry. There is a planar NiC4 unit [d(Ni-C) 2.023(4), 2.032(4) A?] and a nearly trigonal planar coordination of Li at R2N and Et2O as well as Li contacts to nickel [d(Li-Ni) 2.592(2) A?] and to carbon atoms R2NCH2Ni of the piperidinomethyl ligands [d(Li-C) 2.166(7), 2.312(8) A?].
- Steinborn, Dirk,Becke, Frank,Boese, Roland
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p. 2625 - 2628
(2008/10/08)
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- Electrochemical Formation of Dimeric Organostannyl Compounds
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Organosilyl stannanes were formed by electroreduction of the corresponding organostannyl chlorides or distannanes with silyl chlorides.The Sn-C bond formation was also confirmed in the reduction of a mixture of stannyl and alkyl chlorides.
- Ishiwata, Toyoaki,Nonaka, Tsutomu,Umezawa, Masanobu
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p. 1631 - 1634
(2007/10/02)
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- Diorganomagnesium Compounds from Magnesium, Hydrogen, and 1-Alkenes and Their Application in Synthesis
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1-Alkenes are converted in high yields to the corresponding primary diorganomagnesium compounds by transition metal-catalyzed hydromagnesation reaction using catalytically prepared suspended (MgH2*) or dissolved magnesium hydride (MgH2').The most active hydromagnesation catalysts have been found to be combinations of zirconium tetrahalides with MgH2* or MgH2'.The reaction is highly regio- and chemoselective.The diorganomagnesium compounds prepared in situ from magnesium, hydrogen, and 1-alkenes can be applied to the synthesis of organic and organometallic compounds just as Grignard compounds (Scheme 3, reactions 3-11).Dioctylmagnesium undergoes the growth reaction with ethene in the presence of quinuclidine and is oxidized by molecular oxygen in high yield to 1-octanol. Key Words: Magnesium hydride, catalytically prepared / Hydromagnesation reactions / Magnesium, diorgano compounds, preparation from magnesium, hydrogen and 1-alkenes / Magnesium, diorgano compounds, application in syntheses / Magnesium, diorgano compounds, oxidation of
- Bogdanovic, Borislav,Bons, Peter,Konstantinovic, Stanimir,Schwickardi, Manfred,Westeppe, Uwe
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p. 1371 - 1384
(2007/10/02)
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- Evaluation of the aromaticity of borepin: Synthesis and properties of 1-substituted borepins
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The reaction of 1,1-dibutylstannepin with BCl3 gave 1-chloroborepin, which has been converted to a variety of 1-substituted borepins, C6H6BX, where X = OH, O1/2, OCH3, 2,4,6-Me3C6H2, CH2CH2CH2NMe2, F, NH2, N(CH2)5, N(iPr)2, H. 1-Chloroborepin and 1-aminoborepin have been investigated by ab initio methods. All borepins have been studied using 1H NMR, 11B NMR, and 13C NMR spectroscopy. The X-ray crystal structure of 1-chloroborepin gives evidence of a π-delocalized structure. All properties are discussed in terms of the aromatic character of the borepin ring system.
- Ashe III, Arthur J.,Klein, Wolfram,Rousseau, Roger
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p. 3225 - 3231
(2008/10/08)
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- Method for the preparation of tetraalkyl-tin
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A method is disclosed for the preparation of tetraalkyl-tin wherein tin-tetraacetate is first dispersed in tetrahydrofuran and trialkyl-aluminum is slowly added to the dispersion in an amount sufficient to cause complete reaction. The reaction is carried out at a temperature of 80° C. The reaction mixture is then heated to the reflux temperature of the tetrahydrofuran for about 1 to 2 hours and until complete reaction. The aluminum triacetate is then removed and the tetrahydrofuran is distilled off.
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- Organosilicon compounds with functional groups proximate to silicon. XVII. Synthetic and mechanistic aspects of the lithiation of α,β-epoxyalkylsilanes and related α-heterosubstituted epoxides
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A series of α-heterosubstituted epoxides, , has been found to undergo lithiation in the temperature range of -75 to -115 deg C at the C-H bond of the epoxide.The substituent Z could be Me3Si, Ph3Si, n-Bu3Sn, Ph3Sn, PhSO2, (OEt)2PO and Ph; the groups R and R' were H, Ph and n-C6H13; and the lithiating reagents were n-butyllithium, t-butyllithium and lithium diisopropylamide in donor media of THF or TMEDA.The lithiation occurs with retention of configuration and the resulting lithio-epoxide is unstable above 0 deg C, decomposing in a carbenoid manner.The lithiation is facile except for compounds where Z and R (an alkyl or aryl) are cis-oriented; where Z = R3Sn, lithiation occurs by tin-lithium, rather than hydrogen-lithium, exchange.The lithio-epoxides thereby generated can be quenched with various reagents to yield epoxides where the epoxide H has been replaced by D, Me3Sn, R, RCO and COOH.The utility of this procedure in organic synthesis is emphasized.Finally, the possible explanations for the acidity of such α-heterosubstituted epoxides and for the relative stability of the derived lithio-epoxides are considered and assessed.
- Eisch, John J.,Galle, James E.
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p. 293 - 314
(2007/10/02)
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- Synthesis, structure, and reactions of (1-ethoxyethyl)zirconocene chloride, a stable acyclic secondary zirconocene alkyl
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The title compound 1 (Cp2Zr(Cl)CH(CH3)OCH2CH3, Cp = η5-C5H5) has been prepared in good yield by treatment of Cp2ZrCl2 with (1-ethoxyethyl)lithium. Compound 1 is the first example of a stable, structurally characterized secondary zirconocene alkyl derivative which shows no tendency to rearrange to the primary alkyl derivative at room temperature. Carbon monoxide and isocyanides react with 1 to give migratory insertion products without rearrangement of the 1-ethoxyethyl fragment. At high temperatures, 1 decomposes to give ethylene and Cp2Zr(Cl)OCH2CH3, the same products obtained at ambient conditions from the reaction of Cp2ZrHCl (Schwartz's reagent) with ethyl vinyl ether.
- Buchwald, Stephen L.,Nielsen, Ralph B.,Dewan, John C.
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p. 2324 - 2328
(2008/10/08)
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- Reactions of organotin hydrides with lithium diisopropylamide and organolithiums. Reactivities of the intermediates and of the lithium hydride produced
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Equimolar lithium diisopropylamide (LDA) and trimethyltin hydride (TMTH) react in tetrahydrofuran (THF) to form diisopropylamine and (trimethylstannyl)lithium, but in diethyl ether or hexanes 2 mol of TMTH is required for complete reaction and the products are diisopropylamine, hexamethylditin, and lithium hydride. When organic halides are present in this reacting system, reduction to alkane or substitution to form the trimethylalkyltin may occur depending on the nature of the halide. These and other observations suggest that (trimethylstannyl)lithium is formed as an intermediate yielding the tetraalkyltin. Studies on the products and stoichiometries of the reductions of alkyl bromides in ether and hexanes suggest that three reducing agents may be involved: TMTH, [Me3Sn(H)N-i-Pr2]-, and [Me3SnSn(H)Me3]-. The latter predominates in ether, and either or both of the others predominate in hexanes. Formation of methylcyclopentane from 1-bromo-5-hexene suggests involvement of a free radical mechanism. When methyllithium is used instead of LDA in the reaction with TMTH, the products are tetramethyltin and lithium hydride. This reaction can also be diverted to reduction by the presence of primary bromides. Aryl bromides react in both systems, but the yields of either substitution or reduction products are low. The lithium hydride formed in these reactions is extremely reactive as a base as shown by a brief study of its reaction with weak carbon acids and amines and as a nucleophile by its reaction with hexamethylditin to form (trimethylstannyl)lithium in THF.
- Reimann, Werner,Kuivila, Henry G.,Farah, Dan,Apoussidis, Theodorus
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p. 557 - 565
(2008/10/08)
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- Reduction of bis(triorganotin) oxides by metals: An easy route to hexaorganoditins
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Bis(triorganotin) oxides have been reduced in high yield to hexaorganoditins by titanium, magnesium, potassium, and sodium.
- Jousseaume, Bernard,Chanson, Evelyne,Pereyre, Michel
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p. 1271 - 1272
(2008/10/08)
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- Substituted pyranone inhibitors of cholesterol synthesis
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The methyl, ethyl, n-propy, 2-(acetylamino)ethyl, or 1-(2,3-dihydroxy)propyl ester of E-(3R,5S)-7-(4'-fluoro-3,3',5-trimethyl[1,1'-biphenyl]-2-yl)-3,5-dihydroxy-6-heptenoic acid of structural formula: STR1 are HMG-CoA reductase inhibitors useful in the treatment of conditions associated with hypercholesterolemia.
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- DIE CHEMIE DER SCHWEREN CARBEN-ANALOGEN R2M, M=Si, Ge, Sn. X. 7-SILA-NORBORNADIENE: REAKTIONEN MIT HALOGENEN UND THERMOLYSE IN GEGENWART VON METALLORGANISCHEN ODER ORGANISCHEN HALOGENIDEN
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The 7-sila-norbornadienes (I-IV) react rapidly with halogens at -20 to +20 deg C to yield Me2SiHal2 (Hal=Cl, Br, I) and the naphthalene or benzene derivatives (V-VIII).Bromine in CCl4 at 0 deg C, however, caused surprising rearrangement in I giving the 2-bromosilylated naphthalene (IX), since an attack at the alkene group seemed to be preferred.Methylation and methoxylation of IX gave respectively X and XI.Careful hydrolysis of IX yielded the disiloxane XII.Insertions of Me2Si into the Si-Hal, Si-H, Si-C, or Sn-C bonds were not observed at 160-200 deg C, whereas insertions into Sn-Cl or Sn-H bonds occurred smoothly via a one-step mechanism.Halogen is abstracted from different C-Hal bonds leading to Me2SiHal2 and sometimes to Me4Si2Hal2.The degradation of the silylene precursors in these cases is always first order and resembles that of spontaneous thermolysis.
- Appler, Hubertus,Neumann, Wilhelm P.
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p. 247 - 260
(2007/10/02)
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- Nucleophilicity vs. basicity in reactions of n-butyllithium and tert-butyllithium with tetramethylstannane
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The reactions of n-butyllithium and tert-butyllithium with tetramethylstannane have been examined with the objective of determining the degree of competition between proton abstraction from the methyl groups and nucleophilic displacement of these groups f
- Farah, Dan,Karol, Thomas J.,Kuivila, Henry G.
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p. 662 - 666
(2008/10/08)
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- New Reagents, XXXIV. (Diphenylarsino)methyllithium: Synthesis and Preparative Applications
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(Diphenylarsino)methyl iodide (3) was synthesized for the first time (76 percent). (Diphenylarsino)methyllithium (2), stable at 20 deg C, is accessible from 3 (ca. 100 percent) by iodine-lithium exchange with butyl- or phenyllithium and by organoelement-lithium exchange with butyllithium from diphenylarsane (4d; 92 percent). 2, prepared from 4d, gives far better yields of (diphenylarsino)alkanes by the reaction with alkyl halides than 2, obtained from 3.To the contrary, no difference is observed in the reactivity of 2 from 3 or 4d towards aldehydes and ketones.
- Kauffmann, Thomas,Altepeter, Bruno,Klas, Norbert,Kriegesmann, Reinhard
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p. 2353 - 2364
(2007/10/02)
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- Multi Electron Ligands, XV - On the Reactivity of Spirohepta-4,6-diene toward Organolithium and Organoelementlithium Compounds
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The srongly basic organolithium compounds phenyl-, n-butyl-, and tert-butyllithium react with spirohepta-4,6-diene (1) considerably by hydrogen-lithium exchange to give vinylcyclopentadienyllithium (7).On the contrary, the lithium compounds lithium triphenylgermanide and -plumbide react exclusively by opening of the cyclopropane ring giving the products 10a - e, 11a - d, 12, 13a - c, 18a, b, and 19a, b.
- Kauffmann, Thomas,Bisling, Monika,Koenig, Rolf,Rensing, Alfons,Steinseifer, Fritz
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p. 4517 - 4530
(2007/10/02)
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- A NEW PREPARATION OF HEXAALKYLDITINS. 119Sn NMR AND CHROMATOGRAPHIC DATA ON LINEAR POLYTINS
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The reaction of triorganotin oxides and formic acid provides a good route to ditin derivatives.Several new linear polytin compounds have been isolated, and the vicinal and long range 119Sn-119Sn coupling constants determined.A linear relationship has been demonstrated between the logarithm of the HPLC retention time and the number of tin atoms in the compounds.
- Jousseaume, Bernard,Chanson, Evelyne,Bevilacqua, Marcel,Saux, Annie,Pereyre, Michel,et al.
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p. C41 - C45
(2007/10/02)
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- Substituted pyranone inhibitors of cholesterol synthesis
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6-Phenyl-, phenylalkyl- and phenylethenyl-4-hydroxytetrahydropyran-2-ones in the 4(R)-trans stereoisomeric forms are potent inhibitors of cholesterol synthesis by virtue of their ability to inhibit the enzyme, 3-hydroxy-3-methylglutaryl-coenzyme A reductase.
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- SUBSTITUTED PYRANONE INHIBITORS OF CHOLESTEROL SYNTHESIS
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6-Phenyl-, phenylalkyl-and phenylethenyl-4-hydroxytetrahydropyran-2-ones in the 4(R)-trans stereoisomeric forms are potent inhibitors of cholesterol synthesis by virtue of their ability to inhibit the enzyme, 3-hydroxy-3-methylglutaryl-coenzyme A reductas
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- QUELQUES ASPECTS DE LA REACTIVITE DE L'α-CHLORO α-ETHOXYMETHYLTRIBUTYLETAIN: ETHERIFICATION REDUCTRICE DES ALDEHYDES AROMATIQUES ET MISE EN EVIDENCE DE FORMYLTRIBUTYLETAIN LORS DE LA REACTION D'HYDROLYSE
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α-Chloro-α-ethoxymethyltributyltin reacts with aromatic aldehydes and leads to benzyl ethyl ethers with formation of tributyltin chloride and carbon monoxide.Analogously the formation of ethoxymethyltributyltin and tributyltyn chloride on hydrolysis of this new organometallic reagent is explained by a process involving formyltributyltin as an unstable intermediate.This explanation is supported by the observation of an electronic spectrum between 350 and 450 nm during the hydrolysis.
- Quintard, Jean-Paul,Elissondo, Bernard,Mouko-Mpegna, David
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p. 175 - 188
(2007/10/02)
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- INVESTIGATION OF THE DIRECT SYNTHESIS OF TETRABUTYLTIN FROM BUTYL CHLORIDE
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The direct synthesis of tetrabutyltin from butyl chloride, has been investigated, and the various contributing reactions have been identified.A mechanism is proposed for the overall synthesis, which comprises radical-ionic processes for the liberation of metal atoms from the surfaces of the metal powders, followed by formation of bridging intermediates leading to the transfer of butyl groups from zinc to tin, until the synthesis of tetrabutyltin is complete.Although dibutyltin dihalides were shown to be probable intermediates in the process, the known organohalostannate complex Bu4N+ - was not found to be formed under the conditions used.
- Nicholson, John W.,Douek, Josephine A.,Collins, John D.
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p. 173 - 183
(2007/10/02)
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- Process for producing aldehydes
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Described is an olefin hydroformylation process for producing aldehydes utilizing a Pt Group IV-A organometallic catalyst mixture such as (PPh3)2 PtPh-SnPh2 Cl/SnCl2. High yields of aldehydes are produced in high selectivity for the normal isomer, especially when using propylene as the olefin.
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- Pure, unsolvated (α-Methoxyvinyl)lithlum and related acyl anion equivalents via the transmetalation of organotin compounds
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A detailed study of the deprotorution of simple vinyl ethers it reported The major α-deprotooation reaction is accompanied by a tempreature-dependent β-deprotonation process. Pure, unsolvated (α-methoxyvinyl)lithium and related acyl aniom equivalents can be prepared quantitatively from the transmetalation.
- Soderquist, John A.,Hsu, Grace Ji-Ho
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p. 830 - 833
(2008/10/08)
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- SYNTHESIS OF ORGANOTRIALKYLSTANNANES. THE REACTION BETWEEN ORGANIC HALIDES AND HEXAALKYLDISTANNANES IN THE PRESENCE OF PALLADIUM COMPLEXES
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The aryl halides YC6H4X (X=Br or I) have been shown to react with the distannanes (R3Sn)2 (R=n-Bu or Me) in toluene in the presence of or to give the compounds YC6H4SnR3 for (a) R=n-Bu, Y=H, p-OMe, o-Me, p-Me, m-Cl, p-Cl, m-CN, p-COCH3 and m-NO2, and (b) R=Me, Y=H, p-OMe, p-Me, p-CN, p-COCH3, m-NO2 and p-NO2.Benzyl halides YC6H4CH2X (X=Cl or Br) similarly give YC6H4CH2SnR3 for (a) R=n-Bu, Y=H, m-OMe, p-OMe, m-Cl, m-CN, and m-NO2, and (b) R=Me, Y=m-Cl, m-CN, p-CN and m-NO2.These reactions are of special value as preparative procedures in cases in which Grignard or organolithium reagents cannot be used.Allyl chloride and bromide were likewise shown to react with (n-Bu3Sn)2 to give CH2=CHCH2SnBu3, but n-BuCl and n-BuBr gave only a trace of n-Bu4Sn.The mixed dimetallo species n-Bu3SnSiMe3 was shown to react with aryl bromides YC6H4Br (X=H, p-OMe, p-Me, or p-Cl) to give the arylsilicon compounds YC6H4SiMe3, with no aryltin products.
- Azizian, Hormoz,Eaborn, Colin,Pidcock, Alan
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- Cis/trans isomerization of 6-(substituted-aryl-ethenyl)-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-ones
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Biologically inactive cis-6-(substituted-arylethenyl)-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-ones are isomerized to the corresponding anti-hypercholesterolemic trans-isomers by heating in the presence of a heavy metal salt.
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- Polyfluoroalkylthio alcohols, esters and useful compositions therefrom
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Polyfluoroalkylthio alcohols and esters thereof are disclosed with utility as intermediates for the synthesis of fluorochemicals with low free surface energies having oil and water repellent properties. The novel alcohols and esters are obtained by a free radical catalyzed addition of polyfluoroalkylthiols to acetylenic alcohols or esters thereof. The alcohols are employed in preparation of fluorine containing polyurethanes which are useful as finishes to provide oil and water repellency to textiles and as additives to plastics to provide mold release and other desirable properties.
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