Tf2O mediated dehydrative glycosylation was enabled by strained olefins, including beta-(−)-pinene, and inhibited by other typical bases.
Tf2O介导的脱水糖基化反应是由受限烯烃实现的,包括β-(−)-蒎烯,并受到其他典型碱的抑制。
A versatile glycosylation strategy via Au(<scp>iii</scp>) catalyzed activation of thioglycoside donors
作者:Amol M. Vibhute、Arun Dhaka、Vignesh Athiyarath、Kana M. Sureshan
DOI:10.1039/c6sc00633g
日期:——
Among various methods of chemical glycosylations, glycosylation by activation of thioglycoside donors using a thiophilic promoter is an important strategy. Many promoters have been developed for the activation of thioglycosides. However, incompatibility with substrates having alkenes and the requirement of a stoichiometric amount of promoters, co-promoters and extreme temperatures are some of the limitations
Constrained 3,6-Anhydro-Heptosides: Synthesis by a DAST-Induced Debenzylative Reaction, and Reactivity Profile
作者:Abdellatif Tikad、Stéphane P. Vincent
DOI:10.1002/ejoc.201301071
日期:2013.11
We report the first synthesis of a conformationally constrained 3,6-anhydroheptoside analogue of D-glycero-Dmanno-heptopyranose 7-phosphate by a DAST (diethylaminosulfur trifluoride)-induced intramolecular cycloetherification. The reactivity of a series of constrained bicyclic 3,6anhydro-thioheptosides as glycosyl donors was also studied
Novel Stereocontrolled Glycosidations Using a Solid Acid, SO<sub>4</sub>/ZrO<sub>2</sub>, for Direct Syntheses of <i>α</i>- and <i>β</i>-Mannopyranosides
Novel stereocontrolled glycosidations using an environmentally friendly solid acid, sulfated zirconia (SO4/ZrO2), for direct syntheses of α- and β-mannopyranosides have been developed. The glycosidations of the totally benzylated mannopyranosyl fluoride 1 and various alcohols using SO4/ZrO2 in CH3CN at 40 °C for 15 h exclusively gave the corresponding α-mannopyranosides. On the other hand, the corresponding β-mannopyranosides were selectively obtained by the glycosidations of 1 and various alcohols employing SO4/ZrO2 in the presence of molecular sieves 5 Å in Et2O at 25 °C for 15 h.
使用环保固体酸硫酸化氧化锆 (SO4/ZrO2) 的新型立体控制糖苷化,用于直接合成 α- 和 β- 吡喃甘露糖苷,已经开发出来。完全苄基化的吡喃甘露糖基氟化物 1 和各种醇在 CH3CN 中于 40 °C 下使用 SO4/ZrO2 进行糖苷化 15 小时,专门得到相应的 α-吡喃甘露糖苷。另一方面,相应的β-吡喃甘露糖苷是通过1 和各种醇的糖苷化选择性获得的,使用SO4/ZrO2 在分子筛5 Å 的Et2O 存在下在25 °C 15 小时。