Glycosyl Halides and Anomeric Esters as Donors

Abstract

Glycosyl fluorides have been widely and effectively used for O-glycosidation reactions. One of the notable advantages of the glycosyl fluoride as a glycosyl donor is its higher thermal and chemical stability as compared to glycosyl chlorides, bromides, and iodides. Therefore, the glycosyl fluoride can be generally purified by an appropriate distillation and even by column chromatography over silica gel. The use of glycosyl fluoride as a glycosyl donor was first introduced by Mukaiyama et al. in 1981 []. After the first significant advance in this field, a number of effective methods for fluorinating the anomeric center of several types of sugars has been developed. The representative methods for the conversion of a free anomeric hydroxy group of sugars into the fluorine are summarized in Table 1.