_P.-Powell-auth.-Principles-of-Organometallic-Chemistry-Springer-Netherlands-1988

Organo-halides of Group IV
It can be removed by hydrolysis under mildly acidic or basic conditions.
Trimethylsilyl derivatives are thermally stable and are often more volatile than
the precursor alcohols. Derivatives of monosaccharides, for example, can be
analysed by gas-liquid chromatography whereas the parent molecules are far too
involatile and would decompose.
Organotin halides (X= CI. Br) can be prepared by redistribution reactions.
Good yields of R 3 SnCI or of R 2 SnCI 2 are obtained by heating together R 4 Sn and
SnCl 4 in the appropriate proportions. RSnCI, is made from R 4 Sn and excess
SnCl 4 .
3R 4 Sn + SnCI 4
------> 4R,SnCI
R 4 Sn + SnCI 4 ------> 2R 2 SnCi 2
R 4 Sn + 3SnCI 4 ---> 4RSnCI, ( + some R 2 SnCi 2 + excess SnC1 4 )
No Lewis acid catalyst is required (contrast silicon p. 101 ). Methyltin halides
also result from the 'direct synthesis':
Cu
2MeCI + Sn ~ Me 2 SnCi 2 ( 7 5%) + other hali des
31'1 l'
Some reactions of alkyltin compounds are summarized in fig. 4.5. This
SnCL4 + Rli or (R3AL + NaCL) or RMgX
!
R4Sn
SnCL4
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