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Unexpected orthogonality of S-benzoxazolyl and S-thiazolinyl glycosides: application to expeditious oligosaccharide assembly.

ABSTRACT: 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.

SUBMITTER: Kaeothip S

PROVIDER: S-EPMC2642804 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature

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Unexpected orthogonality of S-benzoxazolyl and S-thiazolinyl glycosides: application to expeditious oligosaccharide assembly.

Kaeothip Sophon S Pornsuriyasak Papapida P Rath Nigam P NP Demchenko Alexei V AV

Organic letters 20090201 4

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 ...[more]

PMID: 19161321

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