Recent advances in the synthesis of thiosugars using glycal donors
Tao Xiong, Rui Xie, Cai Huang, Xin Lan, Nianyu Huang, Hui Yao
Abstract
Thiosugars are not only playing important roles in saccharide synthesis but also occur widely in pharmaceutical agents, natural products and S-glycopeptides/proteins, and possess critical biological activities. Many methods have been developed for the syntheses of thiosugars, but most of them adopted saturated-glycosyl donors to give 1-thiosugars only. With the development of olefin-chemistry and transition metal catalysis, numerous protocols of thiosugar synthesis were developed with 1,2-unsaturated-glycosyl donors (glycals) giving different stereoselectivity and regioselectivity. In this review, we have summarized the synthetic methods of thiosugars using glycal donors based on promoters/catalysts, including main-group, transition metal, rare-earth and solid-supported catalysts.