1269657-64-8Relevant academic research and scientific papers
A General Approach to O-Sulfation by a Sulfur(VI) Fluoride Exchange Reaction
Ferraro, Samantha L.,Flynn, James P.,Hwang, Seung,Liu, Chao,Niu, Jia,Yang, Cangjie
, p. 18435 - 18441 (2020/08/25)
O-sulfation is an important chemical code widely existing in bioactive molecules, but the scalable and facile synthesis of complex bioactive molecules carrying O-sulfates remains challenging. Reported here is a general approach to O-sulfation by the sulfur(VI) fluoride exchange (SuFEx) reaction between aryl fluorosulfates and silylated hydroxy groups. Efficient sulfate diester formation was achieved through systematic optimization of the electronic properties of aryl fluorosulfates. The versatility of this O-sulfation strategy was demonstrated in the scalable syntheses of a variety of complex molecules carrying sulfate diesters at various positions, including monosaccharides, disaccharides, an amino acid, and a steroid. Selective hydrolytic and hydrogenolytic removal of the aryl masking groups from sulfate diesters yielded the corresponding O-sulfate products in excellent yields. This strategy provides a powerful tool for the synthesis of O-sulfate bioactive compounds.
Preparation of trifluoroethyl- and phenyl-protected sulfates using sulfuryl imidazolium salts
Desoky, Ahmed Y.,Hendel, Jennifer,Ingram, Laura,Taylor, Scott Douglas
, p. 1281 - 1287 (2011/03/23)
Sulfuryl imidazolium salts (SIS's), a new class of sulfating agents, were prepared bearing the trifluoroethyl (TFE) and phenyl groups, two functionalities that have been used for the protection of sulfate monoesters, by subjecting the corresponding sulfonyl imidazoles with methyl triflate. In contrast, SIS's bearing the electron donating neopentyl and isobutyl groups, two moieties that have also been used for the protection of sulfates, were found to be unstable and could not be isolated though SIS's bearing electron donating aryl groups, such as a p-methoxyphenyl or p-thiomethylphenyl group were readily prepared and are stable compounds. In most instances, TFE-protected phenolic and carbohydrate sulfates were obtained in good yield by reaction of the corresponding SIS's with steroids and carbohydrates. Phenyl-protected carbohydrates were also readily prepared using the corresponding SIS's. Those SIS's having a methyl group at the 2-position of the imidazole ring were, in general, superior sulfating agents to those, which lacked a methyl group at this position. The use of SIS's to prepare TFE-protected sulfates represents a significant improvement of the previous reported procedure, which involved treating unprotected sulfates with trifluorodiazoethane. The TFE protecting group was removed from steroidal sulfates and secondary sulfates in carbohydrates in high yields using NaN3 in warm DMF, conditions that are less vigorous than those previously reported for removing this group. Deprotection of TFE-protected 6-sulfated carbohydrates using NaN3 in warm DMF proceeded in lower yields due to partial desulfation.
