Faculty of Science School of Chemistry

Jonathan White

Associate Professor and Reader

CONTACT DETAILS:

Address: Bio21 Institute, School of Chemistry, University of Melbourne, Parkville, VIC 3010 Australia

Room: 551

 Email: whitejm@unimelb.edu.au

 

Teaching responsibilities

 

 

Field of expertise

Structural Organic Chemistry

Stereoelectronic Effects in Organic Compounds

(a) Stereoelectronic effects of group 4 metals Si to Sn, Fe, S, Se and Te substituents.

Accurate low temperature x-ray structural studies, [1-4] and solution conformational studies [1] are used to probe the ground state effects of silicon and lower Group 4 metal as well as Fe, the chalcogen substituents S, Se and Te [4] , on the structural parameters of substituted esters, alcohols and ethers. Comparison between structure and solution phase reactivity has provided valuable insight into the origin of the electronic effects such as the silicon b,g and d effects, and the nature of neighbouring group participation by chalcogen substituents. [1-4]

 

(b) Applications of the Structure Correlation Principle in Mechanistic Organic Chemistry

Structural changes which occur along a reaction coordinate can sometimes manifest in the ground state of the reactant as measurable deviations of bond distances and angles from 'normal values' along the reaction coordinate. We have demonstrated that the early stages of the retro Diels Alder reaction manifest in the ground state structures of substituted cyclohexenes [5,6] as studied using x-ray crystallography, qualitative information on solution phase reactivity and on sychroniety has been obtained.

 

Metal-Directed Reactions

The utilisation of group 4 metals to direct reactions and rearrangements involving carbenium ion (or   developing carbenium ion) intermediates is another area of interest in this group. We are currently investigating the silicon and tin-directed [7,8] acid catalysed ring opening of silyl substituted epoxides, in addition to silicon and tin-directed ring expansion reactions including the Baeyer Villiger and Tiffeneau-Demjanov reactions. [8]

 

Design and Synthesis of DNA-Minor Groove binding Radiomodifiers

As part of a collaboration with the Peter MacCallum Cancer Institute we are investigating the design, synthesis and biological evaluation of DNA minor groove binding molecules based on HOECHST 33258 [9-12] as modifiers for use in cancer radiotherapy. When the phenyl ring is substituted with electron donating substituents the molecules act as radioprotectors, whereas incorporation of iodide substituents renders the molecules as radiosensitisers. Methyl Proamine is an example of a radioprotecting bibenzimidazole which is currently being evaluated for clinical application.

 

For further information go to the White group research page

 

Selected Publications:
  1. White, J. M.; Clark, C. I. Topics in Stereochemistry 1999, Vol 22, Chapter 3, Ed. S. Denmark. John Wiley and Sons New York (References cited within.)
  2. Green, A. J.; Pigdon, T.; White, J. M.; Yamen, J. J., Org. Chem., 1998, 63, 3943.
    Green, A. J.; Van, V.; White, J. M., Aust. J. Chem. 1998, 51, 555.
  3. White, J. M. ; Lambert, J. B.; Spiniello, M. ; Jones, S. A.; Gable, R. W.; Chem. Eur. J., 2002, 8, 2799-2811.
  4. Birney, D.; Lim, T. K.; Peng, J.; Pool, B. R.; White, J. M., J. Am. Chem. Soc., 2002, 124, 5091-5099.
  5. White, J. M.; Pool, B. R., Org. Letters, 2000, 2, 3505-3507
  6. Badali, F.; Issa, W.; Pool B.; White, J. M., J. Organomet. Chem., 1999, 575(2), 251.
  7. Horvat, S.; Karallas, P.; White, J. M., J. Chem. Soc. Perkin Trans. 1998, 2, 2151.
  8. Clark, C. I.; Martin, R. F.; Labolschovsky, P.; White, J. M., Aust. J. Chem. 1998, 51, 243.
  9. Bateman, S. A.; Kelly, D. P.; Martin, R. F.; White, J. M., Aust. J. Chem., 1999, 52, 291.
  10. Squire, C. J.; Baker, L. J.; Clark, G. R.; Matin, R. F.; White, J. M., Nucleic Acids Res. 2000, 1252.
  11. Clark, G. R.; Martin, R. F.; White, J. M., Nucleic Acids Res. 2000,1259

 
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