Subject organotins

In contrast to this view, but in analogy with the behavior of several antitumor metal complexes, some authors proposed that the DNA is the probable target for cytotoxic activity of organotin(IV) compounds. In this section we survey and compare the most important literature data published to date on this subject. 

Attempts to improve the bioavailability of the organotin(IV) cations by the formation of water-soluble complexes or by their inclusion into )S-cyclodex-trin have also been reported. In spite of their widespread activity, these antitumor organotin(IV) complexes have not yet been subjected to extensive clinical trials in humans. 

About 1000 papers are published annually on organotin chemistry, and we have been able to include only 5% of these. We have deliberately avoided treating in depth those aspects of the subject that have been thoroughly reviewed recently, and, in particular, we have avoided duplicating the excellent surveys of the use of organotin compounds in organic synthesis (4), of " "Sn Mossbauer spectroscopy (5-9), and of Sn NMR spectroscopy (10-12) that are available. 

The older literature on organotin chemistry is reviewed in references (13) to (16), and the periodical surveys are listed in references (17) to (30). Recent reviews of specific aspects of the subject are referred to at the appropriate place in the text, or are listed in references (31) to (34). 

The subject index provides access to the text by way of methods, techniques, reaction types, apparatus, effects and other phenomena. Also, it lists compound classes such as organotin compounds or rare-earth hydrides which cannot be expressed by the empirical formulas of the compound index. 

See the introductory comments in Sections I.A.l and I.A.2 of Chapter 7. This section is complementary to Section II.C above, dealing with trace analysis of tin, however, here attention is paid to the various organotin compounds present in the sample and not only to the overall tin content. It should be pointed out that innumerable examples appear in the literature, showing variations on procedural details required for a particular problem. The present account, although selective to a certain point, does not pretend to be critical on the subject. 

The importance of carbanions a-substituted by heteroatoms in organic synthesis explains the vast amount of literature concerning the use of a-heterosubstituted organotins in transmetallation reactions. As the tin-lithium exchange is assumed to occur with a complete retention of configuration at the carbanion centre639, the enantioselective approach of such stabilized carbanions for synthesis has been the subject of recent developments. 

Much will depend here on the outcome of the present study of the metabolic fate of organotin compounds under environmental conditions. It is generally accepted that the basic types of organotin compounds are subject to the following generalized pattern of physical, chemical and/or biochemical degradation ... 

Organotin hydrides have found much interest in recent years both as synthetic reagents and as the subjects of numerous theoretical investigations. 

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