Transition-metal-free synthesis of aryl 1-thioglycosides with arynes at room temperature
作者:Yao Liu、Xiao-Bing Yu、Xiang-Mei Zhang、Qian Zhong、Li-Hua Liao、Nan Yan
DOI:10.1039/d1ra04013h
日期:——
transition-metal-free protocol for the synthesis of aryl 1-thioglycosides is presented via arynes generated in situ combined with glycosyl thiols in the presence of TBAF(tBuOH)4. The methodology provides a general and efficient way to prepare a series of functionalized thioglycosides in good to excellent yields with a perfect control of the anomeric configuration at roomtemperature. In addition, the reaction
在 TBAF( t BuOH) 4存在下,通过原位生成的芳烃与糖基硫醇结合,提出了一种温和、方便且不含过渡金属的芳基 1-硫糖苷合成方案。该方法提供了一种通用且有效的方法来制备一系列功能化的硫糖苷,并在室温下完美控制异头构型。此外,反应条件耐受多种戊糖和己糖,反应在受保护的单糖和二糖上也能顺利进行。
Palladium-Catalyzed Cross-Coupling Reaction of Thioglycosides with (Hetero)aryl Halides
α- and β-thioglycosides serve as effective nucleophiles for Buchwald–Hartwig cross-couplingreactions using functionalized (hetero)arylhalides. The functional group tolerance on the electrophilic partner is typically high, both benzyl and acetate protecting groups on the carbohydrate are tolerated, and anomer selectivities of thioglycosides are high in all cases studied. The efficiency of this general
Controllable Activation of Pd-G3 Palladacycle Precatalyst in the Presence of Thiosugars: Rapid Access to 1-Aminobiphenyl Thioglycoside Atropoisomers at Room Temperature
作者:Riyadh Ahmed Atto AL-Shuaeeb、Camille Dejean、Mouâd Alami、Samir Messaoudi
DOI:10.1002/asia.201701415
日期:2017.12.14
A controllable method for the functionalization of XantPhos Pd‐G3 precatalyst with thiosugars and thiols has been established. Under mild and operationally simple reaction conditions through just mixing of precatalyst and thiosugars (α‐ or β‐mono‐, di‐ and poly‐thiosugar derivatives) in water at 25 °C for 20 min, a series of 1‐aminobiphenyl thioglycosides that are difficult to synthesize by classical
Preparation of S-aryl thioglycosides from 1-thiosugars via S-arylation was demonstrated under mild reaction conditions. A wide range of protected and unprotected 1-thiosugars derived from glucose, glucosamine, galactose, mannose, ribose, maltose, and lactose underwent cross-coupling reactions with functionalized aryldiazonium salts in the presence of copper(I) chloride and DBU. The desired products