L‐Proline Derived Thioamide Small Organic Molecule for the α‐Stereoselective Synthesis of 2‐Deoxyglycosides

Abstract

L‐Prolinethioamide catalyzes direct stereoselective glycosylation of glycal donors to access 2‐deoxyglycosides under moderate reaction conditions. This proposed glycosylation protocol produced the desired products in up to 88% yield and shows greater tolerance of glycosyl acceptors and a broad substrate scope with better stereoselectivity. This method is also applicable for less nucleophilic acceptors such as phenol. In addition, 1,1′‐linked trehalose‐type analogues can also be accessed through this methodology. Further, mechanistic studies suggest that, in this glycosylation, L‐prolinethioamide operates via Brønsted acid/base catalysis.