Thiourea-Catalyzed Glycosylation of C,N-Diaryl Glycosyl Imidates
Shashiprabha Dubey1,2, Pintu Kumar Mandal1,2
1Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, P.O. Box 173, Lucknow226031, India.
Abstract:
We report a hydrogen bond-mediated glycosylation protocol employing a new class of C,N-diaryl imidate glycosyl donors bearing two para-fluorophenyl groups, enabling highly efficient and stereoselective glycosylation across a broad range of acceptors. A mechanistic study revealed that thiourea catalysts activate the C,N-diaryl imidate glycosyl donors by forming a noncovalent donor-catalyst complex through hydrogen-bonds. Furthermore, the mild activation conditions and distinct reactivity of C,N-diaryl imidate glycosyl donors facilitate their application in various one-pot oligosaccharide synthesis strategies.
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