The trichloroethyl (TCE) group is shown to be a viable protecting group for sulfonates. TCE-protected sulfonates were found to be particularly stable to acid, a key characteristic that led to a straightforward enantioselective synthesis of l-FmocPhe(p-CH(2)SO(3)TCE)OH. This was used as a building block for the solid phase synthesis of an octapeptide corresponding to P-selectin glycoprotein ligand-1 residues 43-50 (PSGL-1(43-50)) in which sulfotyrosine residues 46 and 48 were replaced with (sulfonomethyl)phenylalanine (SmP), an important hydrolytically stable sulfotyrosine mimic.

Type 2 diabetes and obesity are characterised by insulin and leptin resistance. Studies suggest that these may be due to defects in the insulin and leptin signalling pathways. Over the last decade, a considerable body of evidence has been amassed indicating that protein tyrosine phosphatase 1B (PTP1B) is involved in the downregulation of insulin and leptin signalling. Consequently, compounds that inhibit PTP1B have potential as therapeutics for treating Type 2 diabetes and obesity. This review covers recent advances in PTP1B inhibitors with an emphasis on recent attempts to create potent, selective and cell-permeable small-molecule inhibitors.

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Alpha-fluorosulfonamides were prepared by electrophilic fluorination of tertiary sulfonamides using N-fluorobenzenesulfonimide as fluorinating agent and utilizing the dimethoxybenzyl group (DMB) as a new sulfonamide protecting group. Removal of the DMB group with TFA/CH(2)Cl(2) gave primary and secondary alpha-fluorosulfonamides.

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