Oxidative Activation of C-S Bonds with an Electropositive Nitrogen Promoter Enables Orthogonal Glycosylation of Alkyl over Phenyl Thioglycosides

Org Lett. 2017 Oct 6;19(19):5490-5493. doi: 10.1021/acs.orglett.7b02886. Epub 2017 Sep 28.

Abstract

A method for the selective activation of thioglycosides that uses the N+-thiophilic reagent O-mesitylenesulfonylhydroxylamine (MSH) as a promoter is presented. The reaction proceeds via anomeric mesitylensulfonate intermediates, which could be isolated and fully characterized by placing a fluorine atom at the C2 position. In the presence of a soft Lewis acid, glycosylation reaction proceeds at ambient temperature with good yields. It is further demonstrated that it is possible to orthogonally activate S-ethyl in the presence of S-phenyl donors, enabling the design of sequential glycosylation strategies.

Publication types

  • Research Support, Non-U.S. Gov't