19006-69-0Relevant articles and documents
Modelling nucleophilic substitution at silicon in solution using hypervalent silicon compounds based on 2-thiopyridones
Bassindale, Alan R.,Parker, David J.,Taylor, Peter G.
, p. 1059 - 1066 (2007/10/03)
Halodimethylsilylmethyl derivatives of 2-thiopyridones have been prepared. The N-CH2 isomer is favoured with the 6-methylthiopyridone. 13C and 29Si chemical shifts have been used to calculate the extent of sulfur-silicon bond formation and the extent of pentacoordination. The results are consistent with the oxygen analogues and reveal that as expected sulfur is a poorer nucleophile than oxygen. The unsubstituted thiopyridone and the 5-trifluoromethyl derivative favour the S-CH2 isomer. Again the mapping of nucleophilic substitution by nitrogen is in line with sulfur and oxygen nucleophiles, but in this series nitrogen is a poorer nucleophile than expected. The results are discussed in terms of steric strain, the preferences for alkylation of the pyridones and the bond strength of coordination to silicon.
