Thorough mechanistic studies of the alkylation pathway for the activation of glycosyl thioimidates have led to the development of the "thioimidate-only orthogonal strategy". Discrimination among S-thiazolinyl (STaz) and S-benzoxazolyl (SBox) anomeric leaving groups was achieved by fine-tuning of the activation conditions. Preferential glycosidation of a certain thioimidate is not simply determined by the strength of activating reagents; instead, the type of activation--direct vs indirect--comes to the fore and plays the key role.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2642804 | PMC |
| http://dx.doi.org/10.1021/ol802740b | DOI Listing |
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