Organotin acetates

Another major use of organotin compounds is as curing agents for the room temperature vulcanization of silicones the 3 most commonly used compounds are Bu2SnX2, where X is acetate, 2-ethylhexanoate or laurate. The same compounds are also used to catalyse the addition of alcohols to isocyanates to produce polyurethanes. 

Polyvinyl chloride/Polyvinyl acetate Good prevent yellowing. High-molecular-weight organotin stabilizers improve radiation stability color-corrected radiation formulations are available. Less resistant than PVC. 

Thiol compounds 252, 254 Thione compounds 252, 254 Thiosemicarbazides, N-aryl- 248 Thiourea 107, 246,254, 269, 337 -, derivatives 322, 323 Thorium cations 144 Threonine 246 Thymol 153, 197, 198 -, derivatives 288 Tigogenin 59, 195 -, acetate 63 Tigogenone 59,60 Tillmans reagent 256 Tin, cations 144,311,398 -, organic derivatives see Organotin compounds... 

Although this method is not a general procedure, being specific for a-nitroketones, it has several merits to avoid the use of toxic reagents such as organotin compounds. Functionalized ketones have been prepared by this denitration reaction, in which functionalized nitroalkanes are used as alkyl anion synthons. For example, 3-nitropropanal ethylene acetal can be used as synthon of the 3-oxo-propyl anion and 1,4-dicarbonyl compounds are prepared, as shown in Eq. 7.88.135... 

Bis(tributyltin)oxide in antifouling paint was found to change to tributyltin chloride and an unknown organotin species by Allen and coworkers106. The organotin species appear to be held strongly within the paint film. In the case of triphenyltin chloride and triphenyltin acetate, evidence of dephenylation to form diphenyltin and monophenyltin compounds has been obtained. 

Alkynylation of halo acetals. In the presence of ZnCl2 (2 equiv.) the organotin acetylide 1 couples with chloromethyl methyl ether or chloromethyl methyl sulfide to form alkynyl ethers or sulfides, respectively (equation I). 

In sludge anionic and non-ionic surfactants carboxylic acids hhydroxybutyrate hydroxy valerate chloroaliphatic compounds chlorophenols polychlorobiphenyls 4-nitrophenol mixtures of organic compounds chlorinated insecticides, phenoxy acetic acid type herbicides and organotin compounds. 

On the other hand, since no migration resnlted with whether acetic anhydride or benzoyl chloride at room temperature, it is apparent that the results controlled by acyl reagents, where the 3,6-position protected product 37 was obtained with acetic anhydride whereas the 2,6-position protected product 38 was obtained with benzoyl chloride at room temperature, were not brought about by the organotin acyl group migration mentioned above (Scheme 9). 

It has been demonstrated that organotin-mediated multiple carbohydrate esterifications can be controlled by the acytaring reagent and the solvent polarity. When acetyl chloride is used, the reactions are under thermodynamic control, whereas when acetic anhydride is employed, kinetic control takes place. Very good selectivity can furthermore be obtained in more polar solvents. These results can be used in the efficient preparation of prototype carbohydrate structures. 

A recent area of interest has been the mass spectra of organotin pesticides (160,161), for example, triphenyltin acetate that fragments as follows ... 

The syntheses of dithioacetals are generally straightforward [43]. Standard methods may be unselective for multifunctional molecules. Therefore, new procedures have been developed. It has thus been reported that 1,3-dithianes are readily synthesized by reaction of aldehydes, ketones or acetals with 2-stanna-l,3-dithianes under catalysis of organotin triflates [45]. These odourless reagents are prepared from dialkyldichlorotin and 1,3-propanedithiol. 

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