Transition-metal-free synthesis of aryl 1-thioglycosides with arynes at room temperature
A mild, convenient and transition-metal-free protocol for the synthesis of aryl 1-thioglycosides is presentedviaarynes generatedin situcombined 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 room temperature. In addition, the reaction conditions tolerate a variety of the pentoses and hexoses, and the reaction also performs smoothly on protected monosaccharides and disaccharides.
Electrochemical nickel-catalyzed Migita cross-coupling of 1-thiosugars with aryl, alkenyl and alkynyl bromides
Here we report a simple route towards the synthesis of thioglycosides, in which electrochemical cross-coupling is used to form a S-C glycosidic bond from protected and unprotected thiosugars with functionalized aryl bromides under base free conditions. The reaction manifold that we report here demonstrates the power of electrochemistry to access highly complex glycosides under mild conditions.
Alami, Mouad,Messaoudi, Samir,Zhu, Mingxiang
supporting information
p. 4464 - 4467
(2020/05/05)
Ni/Photoredox-Dual-Catalyzed Functionalization of 1-Thiosugars
A general protocol for functionalization of glycosyl thiols has been reported. This protocol is based on a single-electron Ni/photoredox dual-catalyzed cross coupling between 1-thiosugars and a broad range of aryl bromides and iodides as well as alkenyl and alkynyl halides. This base-free method gives access to a series of functionalized thioglycosides in moderate to excellent yields with a perfect control of the anomeric configuration. Moreover, it has been shown that this methodology may be transposed successfully to the continuous-flow photoredox chemistry.