Tetra n-butyltin

The values of k2 and k°2s given in Tables 16 and 17 for brominolysis of tetra-n-propyltin and tetra-n-butyltin enable a value for K, the equilibrium constant for reaction (32), to be estimated using equation (31). Under the conditions given in Table 17, K is found to be 82 l.mole-1, in fair agreement with the reported22 value of 52 l.mole-1. at 25 °C (see Table 2, p. 139). 

Tetra-n-butyltin is oxidised by chromium trioxide (1 1 molar ratio) to yield tri-n-butyltin acetate and compounds derived from the n-butyl group cleaved from the tin atom (mainly n-butyraldehyde and butyric acid)29. In the initial stages of the oxidation, the reaction follows the simple rate expressions v = k2 [Bu Sn] [Cr03]. Values of the second-order rate coefficient for the oxidation of a number of tetraalkyitins by Cr03 in solvent acetic acid at 20 °C were reported29 to be as follows... 

Surface organometallic chemistry (SOMC) has shown high potential for the preparation of supported metal catalysts with desired composition and good dispersion [3]. For example, the controlled hydrogenolysis of tetra-n-butyltin (Sn(/i-C4H9)4) on the surface of group VIII metals leads to well-defined bimetallic catalysts [3-6]. In SOMC on metal supported on oxide, judicious selection of reaction conditions (temperature, initial complex concentration etc.) allows the reaction to occur preferentially between organometallic complexes and metal surface [3,5,6]. 

Beilstein Handbook Reference) BRN 3648237 CCRIS 6322 EINECS 215-960-8 HSDB 6074 NSC 22330 NSC 28131 NSC 65524 Stannane, tetrabutyl- Tetra-n-butylcin Tetra-n-butyltin Tetrabutyl-stannane Tetrabutyltin Tin, tetrabutyl-. 

SYNONYMS Synonyms vary depending upon the specific organic tin compound, (triphenyltin chloride) aquatin, chlorotriphenyltin, fentin chloride, triphenyl chlorostannane, tri-phenylchlorotin. (tetrabutyltin) tetra-n-butyltin, tetrabutylstannane. (stannous-2-ethylhexoate)... 

CAS 1461-25-2 EINECS/ELINCS 215-960-8 Synonyms Tetrabutylstannane Tetra-n-butyltin Tin tetrabutyl... 

Geissler and Kriegsmann" investigated the gas chromatographic behaviour of n-butyltintrichloride, di-n-butyltindichloride, tri-n-butyltinchloride and tetra-n-butyltin. 

They measured the relative retention volumes of the butyltin compounds on ten different liquid phases using a katharometer and hydrogen as carrier gas. Their results in Table 113 clearly show the effect of liquid phase polarity on the relative retention volumes. On non-polar liquid phases the compounds are separated according to their molecular weights, whereas in polar liquid phases the relative retention volumes of compounds containing the Sn-Cl bond increase with increasing polarity of the liquid phase. In the case of Carbo-wax, tetra-n-butyltin is eluted as the first compound. 

They concluded that it was not possible to analyse mixtures of the four n-butyltin-halides since tetra-n-butyltin consistently reacts with n-butyltin chloride to form tri-n-butyltinchloride. Mixtures of n butyltintrichloride, di-n-butyltintrichloride and tri-n-butyl-tinchloride can be successfully analysed in the liquid phase OE 4011 (Figure 126) or GI 7100FF. The analysis of mixtures of di-n-butyl-tindichloride, tri-n-butyltinchloride and tetra-n-butyltin is possible only on Carbowax 20M column (Figure 127). In Table 114 are shown results obtained on this column for a range of synthetic mixtures. 

Procedures for synthesis of ketones based on coupling of organostannanes with acid chlorides have also been developed. The catalytic cycle is similar to that involved in the coupling with organic halides. The scope of the tin compounds to which the procedure can be applied is wide and includes successful results with tetra-n-butyltin. This implies that the reductive elimination step (step c) in the mechanism occurs faster than p elimination of the butylpalladium intermediate. 

The preparation of thiols by nucleophilic displacement reactions using aqueous potassium or sodium hydrogen sulphide under catalytic conditions is not particularly effective. A limited number of simple alkane thiols have been obtained under mild and neutral conditions in moderate yield (70-80%) from the reaction of bis(n-butyltin) sulphide with bromoalkanes in the presence of a ca. twofold amount of tetra-n-butylammonium fluoride [1], but there has been no exploitation of this procedure. 

The influence of temperature on the ortho effect has been evaluated in the alkaline hydrolysis in aqueous DMSO solutions of ortho-, meta- and para-substituted phenyl benzoates (26). The alcoholysis of phthalic anhydride (27) to monoalkyl phthalates (28) occurs through an A-2 mechanism via rate-determining attack of the alcohol on a carbonyl carbon of the anhydride (Scheme 4). Evidence adduced for this proposal included highly negative A 5 values and a p value of 4-2.1. In the same study, titanium tetra-n-butoxide and tri-n-butyltin ethanoxide were shown to act as effective catalysts of the half-ester formation from (27), the mechanism involving alkoxy ligand exchange at the metal as an initial step. ... 

Sodium borohydride-Palladium chloride. Sodium borohydride-Rhodium(lII) chloride. Sodium borohydride-Tin(II) chloride. Sodium cyanoborohydride. Sodium 9-cyano-9-hydrido-9-borabicyclo[3.3.1]nonane. Sodium dithionite. Sodium hydride-Sodium t-amyl oxide-Zinc chloride. Sodium trimethoxyborohydride. Tetra-/i-butylammonium borohydride. Tetra-n-butylammonium cyanoborohydride. Tetra-n-butylammonium octahydrotriborate. Tri-n-butyltin hydride. Triethoxy silane. Triisobutylaluminum-Bis(N-methyl-salicyclaldimine)nickel. Zinc borohydride. REDUCTIVE CYCLIZATION Cobaloximc(I). 

Monoetherification of polyols.12 Monobenzylation and monoallylation of polyols can be conducted conveniently under mild conditions by conversion to the stannylene derivative (dimeric) by di-n-butyltin oxide (5, 189 9, 141). The stannylene is then treated with benzyl bromide or allyl bromide and tetra-n-butylammonium iodide (1 equiv.) in benzene. The same conditions can be used to prepare monomethoxymethyl ethers. Quaternary ammonium bromides are less efficient catalysts than the iodides. These salts also accelerate reaction of stannylenes with acid anhydrides. The mechanism for this activation is not clear it may involve coordination of I" to tin. 

Aceto(carbonyl)cyclopentadienyl(tri-phenylphosphine)iron. 3-Acylthiazolidine-2-thiones. Bis(cyclopentadienyl)titana-cyclobutanes. Bromomagnesium diisopro-pylamide. Cerium(III) chloride. Dichloro-phenylborane. Dimethylphenylsilyllithium. Ethylene chloroboronate. Ketene bis(trimethylsilyl)ketals. Mandelic acid. Norephedrine. Potassium fluoride-Alumina. (S)-(—)-Proline. Tetra-n-butylam-monium fluoride. Tin(IV) chloride. Tin(II) trifluoromethanesulfonate. Titanium(IV) chloride. Tri-n-butyltin fluoride. Trityl perchlorate. 

HOMOALLYLIC ALCOHOLS Allyl tri-methyltin. lodomethyltri-n-butyltin. (+)-3-Phenyl-2,3-bornanediol. Tetra-n-butylammonium fluoride. 

Cyclopropenone (I). Breslow and Oda" have effected the preparation and isolation of pure recrystallized cyclopropenone (I, m.p. —29 to —28 ) by reduction of tetra-chlorocyclopropenc in paraffin oil with tri-n-butyltin hydride under argon. A mixture... 

Thallium(I) cyanide was introduced by Taylor and McKillop as a reagent. Aromatic and heteroaromatic acyl cyanides are produced in go yield, whereas aliphatic acid halides lead under these conditions mainly to dimerization products. 18-Crown-6 is a good catalyst for the preparation of cyanoformate in methylene chloride with potassium cyanide and chloroformates. Similarly, tetraethylammonium cyanide gives cyanoformates in high yield under very mild conditions. Aroyl cyanides are generated easily by phase transfer catalysis with tetra-n-butylammonium bromide. Tri- -butyltin cyanide proved successful only with aromatic acid halides, leading to dimerization products with aliphatic compounds. ... 

Mono-n-butyltin tris(j-octylmercaptoacetate) combines improved early color with shortened longterm stability. This is due to its intermediate Lewis acid character between that of diisooctyl bis(t-octylmercaptoacetate) and tin tetra(i-octylmercaptoacetate). The decreased effectiveness of tri-n-butyltin i -octylmercaptoacetate may be ascribed to the increased reluctance to coordination by the tin atom, due to presence of the third alkyl (n-butyl) group. Additionally, the use of trialkyltin derivatives in PVC stabilization has been avoided because of their toxicity. 

Cyclopropenone (3) has been prepared for the first time by reduction of tetra-chlorocyclopropene (1) with 2 equivalents of tri-n-butyltin hydride 11 careful hydroly-... 

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