Organotin compounds toxicity

For example, the toxic organotin compound, tri-n-butyl tin, damages the endoplasmic reticulum and interacts with thiols in the Ca2+ pump such that the intracellular Ca2+ concentration rises to 500 to 600 pM. This is shown in Figure 6.12. 

Recently, an alternative synthesis route has been described that prevents the use of both the expensive and moisture-sensitive Re207 as well as of the toxic organotin compounds. This route uses acetyl perrhenate as the rhenium source and methylzinc acetate as the methylating agent. Acetyl perrhenate can be obtained by treatment of... 

In contrast to the organotin hydride reactions, the electrochemical process is thought to proceed via the bicyclo[3.1.0]hexanolate. The method constitutes an alternative methodology which avoids toxic organotin compounds. 

In spite of their known toxicity, organotin compounds are still invaluable in cross-coupling reactions because of the large variety of residues on tin that can be transferred. The main advantage of organotins over derivatives of other elements is the ease of their preparation and their stability once prepared. The... 

Triethyltin acetate is the most toxic organotin compound to mammals with a LD50 rat = 4 mg/kg." For comparison, the tributyltin acetate has a LD50 of -400 mg/kg." In general, the toxicity cutoff for mammals is at the butyltin, with longer chains relatively nontoxic and shorter chains somewhat toxic. ... 

Toxic Reactions of the Skin Irritation is the most common reaction of the skin. Skin irritation is usually a local inflammatory reaction. The most common skin irritants are solvents dehydrating, oxidizing, or reducing compounds and cosmetic compounds. Acids and alkalies are common irritants. Irritation reactions can be divided into acute irritation and corrosion. Necrosis of the surface of the skin is typical for corrosion. Acids and alkalies also cause chemical burns. Phenols, organotin compounds, hydrogen fluoride, and yellow phosphorus may cause serious burns. Phenol also causes local anesthesia, in fact it has been used as a local anesthetic in minor ear operations such as puncture of the tympanous membrane in cases of otitis. ... 

Similarly, while the main products used as stabilizers in PVC are mono- and disubstituted compounds, owing to the chemistry involved in their production, trisubstituted organotin compounds will comprise a small fraction of the total amount. This could be significant in assessing the toxicity of the compounds (see below). 

Table 23 Toxicity of organotin compounds to aquatic organisms. ...

Fig. 2. Acute toxicity of organotin compounds to freshwater aquatic organisms.

Jensen KG, Onfelt A, Wallin M (1991b) Effects of organotin compounds on mitosis, spindle structure, toxicity and in vitro microtubule assembly. Mutagenesis, 6(5) 409-416. 

Seinen W, Vos JG, van Spanje I, Snoek M, Brands R, Hooykaas H (1977a) Toxicity of organotin compounds. II. Comparative in vivo and in vitro studies with various organotin and organolead compounds in different animal species with special emphasis on lymphocyte cytotoxicity. Toxicology and Applied Pharmacology, 42(1) 197-212. 

The Stille reaction has developed as a popular protocol for the formation of C-C bonds due to the air- and moisture-stability as well as functional group compatibility of organotin compounds. Together with the Suzuki-Miyaura coupling it is one of the most powerful methods for the synthesis of molecules containing unsymmetrical biaryl moieties. However, despite its efficiency, this versatile reaction has slowly been displaced by other procedures that avoid the use of highly toxic organostannanes. 

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... 

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