Fundamental studies on 2,4,6-trichlorophenyl sulfonate esters

This thesis describes the application of 2,4,6-trichlorophenylsulfonate esters in the synthesis of sulfonamides. The sulfonamide unit is an important structural motif due to its frequent occurrence in a range of pharmaceuticals, particularly antibiotics. Sulfonamides can be readily synthesised from pentafluorophenyl (PFP) sulfonate esters and as an expansion to this 2,4,6 trichlorophenyl (TCP) sulfonates have been developed. These have the added advantage of lower toxicity and reduced cost of trichlorophenol. TCP sulfonates can be synthesised directly from sulfonic acids via activation by triphenylphosphine ditriflate in moderate to excellent yields. These compounds can then be utilised in the synthesis of sulfonamides and suitable conditions for reactions with both simple aliphatic amines and more challenging anilines have been found. The differing reactivity’s of the TCP and PFP sulfonate esters have been exploited in selective sulfonamide formation. The greater stability of TCP sulfonate in comparison to PFP sulfonate also means that a broader range of transformations can be achieved in its presence. This has been shown particularly in the application of palladium chemistry to synthesise more elaborate TCP sulfonates. Also, the synthesis of novel amino acids have been targeted inorder to further demonstrate the stability of the group when performing more diverse reactions on remote sites in the molecule.

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

UCL (University College London)

Year dc:date.issued

2009

Author dc:creator

• Geldeard, L.J.

• Department of Chemistry

Language dc:language

en, eng