Structural, Mechanistic and Synthetic Silicon Chemistry

My research involves extensive collaboration with Professor Alan Bassindale in a wide variety of silicon chemistry research interests.

One of our main areas of focus is the development of new materials based upon silsesquioxane cages. We are interested in the synthesis of T8, T10 and T12 cages together with a range of silsesquioxanes with predetermined geometry. Such arrangements of silicon atoms lead to 'octopus molecules' with pendant arms spreading radially from the centre. We are at present developing methodologies for the preparation of novel cage and partial cage molecules with a range of functionalities such as liquid crystals, metal ligands and DNA sequences.

Another project involves an investigation of the mechanism of substitution at silicon. This involves the synthesis of hypervalent silicon compounds that are transition state models for substitution (for example, silyl-pyridone complexes - right). Structural analysis using NMR and X-ray crystallography reveals the substitution trajectory. We are also examining the mechanism of substitution at pentacoordinate silicon using diastereotopic hypervalent silicon compounds.

For a number of years our group has been interested in the use of silicon in synthesis. Recently we have been involved in developing new silane-based reductions and the use of ionic liquids as both solvent and nucleophile in selected organosilicon conversions. We have developed a number of routes to silyl aziridines and examined their ring opening reactions under the influence of both nucleophiles and electrophiles.

The use of silicon derivating agents in analysis is widespread. However, the use of chiral silicon in enantiomeric separations has not been studied a great deal. We are synthesizing new chiral silicon derivatising agents which form diastereoisomers when reacted with chiral substrates, thus enabling simple chromatographic enantioselective separation.

Selected Publications:

1. "Trimethylsilylsulfonyl chloride as a source of sulfur trioxide: a novel synthesis of sultones"; A.R. Bassindale, I. Katampe, M.G. Maesano, P. Patel and P.G. Taylor; Tetrahedron Lett.; 40, 1999, 7417.



2. "Modelling nucleophilic substitution at silicon in solution using hypervalent silicon compounds based on 2-pyridones"; A.R. Bassindale, M. Borbaruah, S.J. Glynn, D.J. Parker, P.G. Taylor; J. Chem. Soc., Perkin Trans. 2; 1999, 2099.
   
   
3. "Ring opening reactions of 2-trialkylsilylaziridines"; A.R. Bassindale, P.A. Kyle, M-C. Soobramanien and P.G. Taylor; J. Chem. Soc., Perkin Trans. 1; 2000, 439.
   
   
4. "The synthesis of some 2-trimethylsilylaziridines"; A.R. Bassindale, P.A. Kyle and M-C. Soobramanien and P.G. Taylor; J. Chem. Soc., Perkin Trans. 1; 2000, 1173.
   
   
5. "Modelling nucleophilic substitution at silicon in solution using hypervalent silicon compounds based on 2-thiopyridones"; A.R. Bassindale, D.J. Parker and P.G. Taylor; J. Chem. Soc., Perkin Trans. 2; 2000, 1059.
   
   
6. "Improved simple synthesis of cyclic sulfates from trimethylsilyl chlorosulfonate"; A.R. Bassindale, I. Katampe and P.G. Taylor; Can. J. Chem.; 78, 2000, 1479.
   
   
7. "Modelling SN2 nucleophilic substitution at silicon by structural correlation with X-Ray crystallography and NMR spectroscopy"; A.R. Bassindale, D.J. Parker, P.G. Taylor, N. Auner and B. Herrschaft; J. Organomet. Chem.; Submitted for publication.
   
   
8. "Chemoselective methylation of amides and heterocycles using chloromethyldimethylsilyl chloride"; A.R. Bassindale, D.J. Parker, P. Patel and P.G. Taylor; Tetrahedron Lett.; 25, 2000, 4933.



9. "Modelling nucleophillic substitution at silicon in solution using hypervalent silicon compounds based on 2-pyridones"; A.R. Bassindale, M. Borbaruah, S.J. Glynn, D.J. Parker and P.G. Taylor; J. Chem. Soc., Perkin Trans. 2; 1999, 2099.



10. "Modelling nucleophillic substitution at silicon using hypervalent silicon compounds based on ureas"; A.R. Bassindale, S.J. Glynn and P.G. Taylor; J. Organomet. Chem; 606, 2000, 125.



11. Modelling nucleophillic substitution at silicon using hypervalent silicon compounds based on urea ligands"; A.R. Bassindale, S.J. Glynn, P.G. Taylor and N. Auner. J. Organomet. Chem.; 606, 2001, 132.



12. "Reactions of silamorpholines and acylsilamorpholines with electrophillic reagents. X-ray structure of products including a pentacoordinated silicon compound"; A.G. Shipov, E.P. Kramarova, E.A. Mamaeva, O.A. Zamyshlyaeva, V.V. Negrebetsky, Y.E. Ovchinnikov, S.A. Pogozhikh, A.R. Bassindale, P.G. Taylor and Y.I Baukov; J.Organomet.Chem; 606, 2001, 139.

Other Interests:

I am the proud owner of a West Ham United season ticket and have supported them for over 40 years through thick and thin (mainly thin!). I look forward to meeting many members of my family at the matches.