Abstract
The [3,3]-sigmatropic allyl cyanate/isocyanate rearrangement of glycals in the presence of O-, N-, and C-nucleophiles afforded β-N-glucosyl and galactosyl carbamates, ureas, and amides in good yields. The unsaturated products were elaborated to N-glycosides by dihydroxylation, to 1,3-diaminosugars by tethered aminohydroxylation, or to 1,2-diaminosugars by iteration of the sigmatropic rearrangement. This metal-free methodology represents an excellent and general method for the stereoselective synthesis of N-glycosides and diamino sugars with complete transmission of stereochemical information.
Highlights
The [3,3]-sigmatropic allyl cyanate/isocyanate rearrangement of glycals in the presence of O, N, and C-nucleophiles afforded β-Nglucosyl and galactosyl carbamates, ureas, and amides in good yields
N-Glycosides (1-aminosugars and derivatives)[2] are a subclass which may serve as synthetic intermediates, besides playing a key role in N-linked glycoproteins involved in many recognition events or in nucleosides and antibiotics.2b Representative examples (Figure 1) include the N-acetyl-D-glucosamine asparagine moiety 1, a key agent in cell-recognition and signal transduction,[3] glycocinnamoylspermidines 2, broad spectrum antibacterial agents,[4] staurosporine 3, displaying anticancer activity,[5] and trehazoline 4, a potent and specific inhibitor of trehalase.[6]
Known Procedures for the Synthesis of NGlycosides from Glycals and the Strategy Reported Based on the Allyl Cyanate/Isocyanate Rearrangement versatility of the resulting isocyanates
Summary
The [3,3]-sigmatropic allyl cyanate/isocyanate rearrangement of glycals in the presence of O-, N-, and C-nucleophiles afforded β-Nglucosyl and galactosyl carbamates, ureas, and amides in good yields. We report our results on the application of the allyl cyanate/isocyanate rearrangement to glycals to give Nglycosides (Scheme 1, route d) and diaminosugar derivatives.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.