Tin to Other Metal Exchanges

The transmetallation was applied to the preparation of vinyl, alkynyl and aryl-boranes via a tin-to-boron exchange. Noticeable examples include the preparation of organoborane Lewis acids [369], the synthesis of alkynyldihaloboranes and their Diels-Alder reaction with 1,3-dienes [370], the formation of cyclooheptatrienyl(di-propyl)borane [371] and the preparation of 1-benzoborepines [372]. In addition to this, the transmetallation tin-to-boron can be applied to aUylboron reagents as mentioned in Section 6.3.I.2.2. 

Finally, several other transmetallations such as tin-to-magnesium [373], tin-to-indium [374], tin-to-stibin [372] and tin-to-arsenic [375] are reported as well. 

To be complete one should add the extremely rich tin hydride chemistry, or the halodestannylation reaction as well as the creation of various carbon-heterode-ment bonds. We should also add the use of tin oxides or hydroxides as protecting groups in polyol chemistry, the use of organotins as catalysts for many reactions such as transesterifications or amide formation. Finally, we could also mention the use of optically active organotin Lewis acids as efficient chirality inductors. All of these reactions, which are not covered in this chapter tend to prove that the use of organotins for organic synthesis is now undoubtedly established and is not limited to the carbon-carbon bond formation with the aforementioned reactions. 

Migita, Chem. Lett., 1977, 301-302. For an historical account of the Stille reaction see M. Kosugi, K. Fugami, 

31 For a review on the use fluorinated orga-nometallics in organic synthesis see  

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