CARB 10 |
| Recently, the synthesis of large homogeneous glycopeptides became possible by a newly emerging technique, i.e. native chemical ligation, in which a peptide thioester and another peptide with an N-terminal cysteine are chemoselectively coupled. There is now a great demand for glycopeptides and (glyco)peptide thioesters, however, their synthesis by conventional methods is not straightforward. We focus on the development of a unique photochemical acylation method, which is predestined for the generation of amides and thioesters, when neutral conditions are essential for success. N-acyl-nitroindolines photoacylate nucleophiles such as amines and thiols in a number of different polar and non-plolar solvents. We take advantage of this chemistry when we generate N-glycopeptides, as well as peptide-alpha-thioesters. The latter can be synthesized on a photoreactive solid support using the Fmoc/t-Bu strategy. Peptide thioesters are directly photoreleased when the resin is illuminated with UV-light in the presence of a mercaptan. |
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Wolfrom/Isbell/New Investigator Award Symposium
1:30 PM-5:15 PM, Sunday, August 19, 2007 BCEC -- 162B, Oral
Division of Carbohydrate Chemistry |