Organotin compounds conversion

TBTs also cause inhibition of the P450 of monooxygenases. In fish and in the common whelk, TBT causes conversion of P450s to the inactive P420 form (Pent et al. 1998, Mensink 1997). In fish, inactivation was also found with TPT, and was related to the inhibition of ethoxy resorufin deethylase activity (EROD) activity. In these studies, organotin compounds were found both as substrates and deactivators of the hemeprotein (cf. the interaction of organophosphates with B-type esterases). 

Low-molecular weight organotin compounds are known to easily undergo chemical conversions upon UV-irradiation1). However, the photochemistry of organotin polymers is still obscure. 

Conversion of the organotin chlorides into fluorides, bromides, or iodides is usually carried out with the sodium halide in acetone, and residual organotin compounds are often removed as the insoluble organotin fluorides. The fluorides can then be converted back into the bromides, chlorides, or iodides (and exchanges by other halides can be brought about with aqueous ammonium halides at room temperature).332 A 2 1 mixture (solid solution) of CsF and CsOH, mixed with silica gel, also provides a very convenient way of removing organotin halide byproducts from solution.333... 

The most toxic of the organotin compounds are the trialkyltins, followed by the dialkyltins and monoalkyltins. The tetraalkyltins are metabolized to their tri-alkyltin homologs their effects are those of the trialkyltins, with severity of effects dependent on the rate of metabolic conversion, hr each major organotin group, the ethyl derivative is the most toxic. ... 

Cremer JE. 1958. The biochemistry of organotin compounds The conversion of tetrathyltin into triethyltin in mammals. Biochem J 68 685-692. 

Figure 2.17. Electron spectroscopy for chemical analysis ESCA) spectra of organometallic polymer films before and after exposure to oxygen plasma. The silicon 2p transition page 99) is shifted from 99.7 to 102.4 eV. The magnitude of the shift is consistent uMh conversion to SiO, where x is between 1.5 and 2. The Sn 3d transitions of the organotin compound above) undergo a similar shift 1.7 eV), consistent with generation of a SnOx surface, where x is again between 1.5 and 2. Argon sputter etching followed by ESCA analysis indicates that these oxide films are less than 100 A thick.

Ferrier RJ (2001) Direct Conversion of 5,6-Unsaturated Hexopyranosyl Compounds to Functionalized Glycohexanones. 215 277-291 Frey H, Schlenk C (2000) Silicon-Based Dendrimers. 210 69-129 Fugami K, Kosugi M (2002) Organotin Compounds. 219 87-130 Fuhrhop J-H,see Li G (2002) 218 133-158... 

A completely different approach to the total synthesis of enterobaetin has been reported by Shanzer and Libman 100>. This is based on a single-step conversion of the tritylated serine-lactone to the cyclic triester enterobaetin backbone via the use of a cyclic organotin compound as template. This is followed by subsequent replacement of the trityl protecting groups by catechol residues to yield enterobaetin. 

Nakamura reported that the ultrasound-promoted reaction of tin hydride with alkenes in the presence of air results in the addition of stannyl and hydroxyl groups across the double bond (hydroxystannylation) (Scheme 16). This procedure is the first example of the conversion of alkenes to hydroxylated organotin compounds... 

The use of stoichiometric amounts of tin hydride in the conversion of 44 to 45 could be perceived as a problem due to the toxicity of organotin compounds. The problem was addressed by developing a method that was catalytic in tin. Basically the trimethyltin iodide produced during this free radical reduction was recycled through trimethyltin hydride via reduction with sodium borohydride. 

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