Trimethyltin chloride, reaction

The methyl-[14C]-dimethyltin chloride was used to compare the performance of packed and megabore capillary columns in a gas chromatographic analysis for separating mixtures of a carbon-14 labelled trimethyllead chloride, tetramethyltin, dimethyltin dichloride and methyltin trichloride. The megabore column was able to separate all four methyltin compounds quickly, i.e., before the tetramethyltin decomposed into trimethyltin chloride and dimethyltin dichloride (equation 47), a reaction which did occur on the packed columns. Thus, the megabore column enabled the determination of the precise distribution of the various methyltin compounds in an environmental sample. The packed columns, on the other hand, could not separate dimethyltin dichloride and the methyltin trichloride and allowed significant decomposition of the tetramethyltin during the 15 minutes the analysis required. 

The various tetraalkyltin compounds were then identified and quantitated by GC MS and gas chromatography-atomic absorption analyses. The results indicated that tin(II) chloride in the simulated sea water was converted into methyltin trichloride and dimethyltin dichloride. The tin(IV) chloride, on the other hand, only formed methyltin trichloride. No trace of trimethyltin chloride was found from either tin(II) or tin(IV). The maximum amount of methyltin trichloride was formed near pH = 6 and at a salinity of 28%. The rate expression for the reaction is... 

A third method of estimating solvent basicity is provided by the donor number concept 14 ). The donor number of a solvent is the enthalpy of reaction, measured in kcal per mole, between the solvent and a Lewis add such as antimony (V) chloride. (Other Lewis acids, such as iodine or trimethyltin chloride, may be used, but the scale most often reported is that for SbCl5.) Available values for the SbCls donor number have been included in Table 1. Plots of the Walden product versus solvent basicity (A//SbC1 ) for several solvents are shown for lithium, sodium, and potassium ions in Fig. 10 and for the tetraalkylammon-... 

We note that while tin reagents have often been employed for the organoboron halides/ the use of organostannanes as starting materials can also be applied to the synthesis of heavier group 13 derivatives. In the context of polyfunc-tional Lewis acid chemistry, this type of reaction has been employed for the preparation of ort/ o-phenylene aluminum derivatives. Thus, the reaction of 1,2-bis(trimethylstannyl)benzene 7 with dimethylaluminum chloride, methylaluminum dichloride or aluminum trichloride affords l,2-bis(dimethylaluminum)phenylene 37, l,2-bis(chloro(methyl)aluminum)phenylene 38 and 1,2-bis(dichloroalumi-num)phenylene 39, respectively (Scheme 16). Unfortunately, these compounds could not be crystallized and their identities have been inferred from NMR data only. In the case of 39, the aluminum derivative could not be separated from trimethyltin chloride with which it reportedly forms a polymeric ion pair consisting of trimethylstannyl cations and bis(trichloroaluminate) anions 40. 

The enantioselective addition of the amino organolithium reagents consists of two stereo-controlled reactions, the asymmetric deprotonation (equation 14) and the following addition to electrophiles. The stereochemical course of the addition depends on the electrophile E. In the cases where heterocyclic enone or a,-unsaturated lactones are the electrophiles (entries 5-7), the addition proceeds with retention of configuration. In contrast, with the other electrophiles in Table 10 and trimethyltin chloride in equation 15, the addition proceeds with inversion of configuration. In the addition which proceeds with retention of configuration, a pre-complexation between the electrophiles and lithium may be involved (equation 16). 

Trimethyltin chloride can be purchased from Strem Chemicals, Inc. or prepared by the reaction of tetramethyltin with tin tetrachloride as follows To a 100-mL, round-bottomed flask, equipped with a magnetic stirring bar, and a septum, and a gas Inlet connected to a static argon atmosphere, containing 41.2 g (0.230 mol) of tetramethyltin cooled to -20°C with a dry ice/carbon tetrachloride slurry, is added 9.0 mL (0.0769 mol) of tin tetrachloride at a slow dropwise rate. After the addition is complete, the... 

The progress of the reaction is conveniently monitored by gas chromatography on a 1/8" x 6 column packed with 6X SP-2100 on Supelcoport, 80-100 mesh, operated at 50°C for 4 min, then heated at 15°C/min to 250°C. The relative retention times are 4.0 min for trimethylvinyltin, 6.5 min for trimethyltin chloride, 13.1 min for 4-tert-butylcyclohexen-l-yl trifluoromethanesulfonate, and 14.7 min for l-(4-tert-butylcyclohexen-l-y1)-2-propen-l-one. Because of the extreme Volatility of trimethylvinyltin, it may be necessary to add additional small amounts of this reagent in order to drive the reaction to completion. 

Although no coordination complexes of tetraalkyltins with nucleophiles (i.e. Lewis bases) have been reported, it is known that trialkyltin chlorides can form coordination complexes with various Lewis bases. Bolles and Drago38 have shown that trimethyltin chloride forms 1 1 complexes with bases such as acetone, acetonitrile, dimethylsulphoxide, and pyridine. All of these complexes are formed exothermally (in inert solvents such as CC14), with values of Af/299 ranging from —4.8 to —8.2 kcal.mole-1 for the reaction... 

Cyanamides are pseudo-halide nitrogen ligands that are readily coordinated to metals. A novel compound is 2-cyanaminofluoren-9-one (HL4)24. Its thallium salt T1+(L4)-(Scheme 7) is useful as a transmetallating agent in a reaction with trimethyltin chloride to produce the corresponding tin cyanamide complex [SnMe3L4] (Scheme 8). 

By appropriate choice of the reactants and the reaction conditions, a phenol-substituted carboxylic acid may react with an organotin compound to give both an organotin ester and an organotin aryl oxide within the same molecule. The reaction of trimethyltin chloride with 4-hydroxy-3-methoxybenzoic acid (HVAH) in the presence of water and pyridine at 130 °C in a sealed tube gave the unique two-dimensional coordination polymer 134 (equation 2)286. 

The reaction of higher alkyl chlorides with tin metal at 235°C is not practical because of the thermal decomposition which occurs before the products can be removed from the reaction zone. The reaction temperature necessary for the formation of dimethyltin dichloride can be lowered considerably by the use of certain catalysts. Quaternary ammonium and phosphonium iodides allow the reaction to proceed in good yield at 150—160°C (109). An improvement in the process involves the use of amine—stannic chloride complexes or mixtures of stannic chloride and a quaternary ammonium or phosphonium compound (110). Use of these catalysts is claimed to yield dimethyltin dichloride containing less than 0.1 wt % trimethyltin chloride. Catalyzed direct reactions under pressure are used commercially to manufacture dimethyltin dichloride. 

A solution of 9.66 g (0.05 mol) of trimethyltin chloridef is prepared in 20 mL of dry diethyl ether. The solution is cooled to 0° and is slowly injected through the serum cap into the lithium cyclopentadienide solution. This operation is carried out over a period of 1 hr with continuous stirring, during which time the white precipitate gradually becomes buff-colored. When all of the trimethyltin chloride solution has been added, the flask is allowed to reach room temperature and the reaction mixture is finally gently refluxed for 6 hr. 

The tin amide, formed in situ by treating an N-H substrate with -butyllithium, followed by addition of trimethyltin chloride, for one-pot bromination showed great selectivity for the reaction of indole and carbazole (Equations 76 and 77) <20020L2321>. In both cases, the bromination gave a single product in good yield, 80% and 69% for indole and carbazole derivatives, respectively. 

A solution of 2.8 mmol ofj-BuLi in cyclohexane/isopentane in 8 mL of F.t2Ois cooled to —78 °C and treated with 2.9 mmol of (-(-sparteine. After 10 min stirring a solution of 2.0 mmol of the spiro-carbamate 17 in 2 mL of Et20 is injected and the mixture is stirred for 5-6 h at —78 C. After addition of 3.5 mmol of trimethyltin chloride the reaction mixture is stirred for 16 li at —78 C. Workup is carried out as usual with 10 mL of Et2O/10 mL of 2 N HC1. and the crude product is purified by flash chromatography (silica gel. Et20/pentane mixtures). 

A number of reactions are known which appear to involve the formation of oligostannanes by the insertion of stannylene units into a bond to tin, but most of these have little preparative value. For example, hexamethylditin reacts with trimethyltin chloride or dimethyltin dichloride to give, amongst other products, oligodimethylstannanes, (Me2Sn) , apparently by insertion of Me2Sn into SnSn or SnCl bonds.67-68... 

The trimethyltin fluoride is generated in situ or can be added initially. The advantage of this reagent is that it is less volatile than trimethyltin chloride, not easily absorbed through the skin and can be filtered off at the end of the reaction, rather than distributed in both the organic and aqueous waste streams. 

The resin-bound trialkyltin halide developed for this reaction required higher catalytic loadings (30-100%) to obtain reasonable yields of coupled product, (Scheme 5.8.12), presumably reflecting the availability of the catalytic site in the biphasic mixture. Tin contamination of the column purified product, however, was <5-60 ppm compared with >500 ppm obtained for the free trimethyltin chloride-catalyzed reaction. 

The Stille coupling reaction is the most versatile method among all Pd-catalyzed crosscoupling reactions with organometallic reagents. By lithiation of 4-methyloxazole with H-BuLi and subsequent quenching with trimethyltin chloride, Dondoni et al. prepared 2-trimethylstannyl-4-methyloxazole [39], which was then coupled with aryl- and heteroaryl-halides to provide the expected 2-aryloxazole. Thus, 2-trimethylstannyl-4-methyloxazole was coupled with 3-bromo-pyridine to afford oxazolylpyridine 35. 

TRIMETHYLTIN HYDRIDE (1631 -73-8) (CH3)3SiCF=CF2 High acute toxicity. Reacts with water, producing highly flammable hydrogen gas. Violent reaction with oxidizers. See also trimethyltin chloride. 

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