Stereoselective 1,2-<i>cis</i> Furanosylations Catalyzed by Phenanthroline
作者:Hengfu Xu、Richard N. Schaugaard、Jiayi Li、H. Bernhard Schlegel、Hien M. Nguyen
DOI:10.1021/jacs.2c02063
日期:2022.4.27
furanosylation method promoted by phenanthroline catalysts under mild and operationally simple conditions. NMR experiments and density functional theory calculations support an associative mechanism in which the rate-determining step occurs from an inverted displacement of the faster-reacting phenanthrolinium ion intermediate with an alcohol nucleophile. The phenanthroline catalysis system is applicable
Catalytic Stereoselective 1,2-<i>cis</i>-Furanosylations Enabled by Enynal-Derived Copper Carbenes
作者:Bidhan Ghosh、Adam Alber、Chance W. Lander、Yihan Shao、Kenneth M. Nicholas、Indrajeet Sharma
DOI:10.1021/acscatal.3c05237
日期:2024.1.19
and their stereoselective synthesis remains a significant challenge. In this vein, we have developed a stereoselective approach to 1,2-cis-furanosylations using earth-abundant copper catalysis. This protocol proceeds under mild conditions at room temperature and employs readily accessible benchtop stable enynal-derived furanose donors. This chemistry accommodates a variety of alcohols, including primary
Stereospecific Furanosylations Catalyzed by Bis-thiourea Hydrogen-Bond Donors
作者:Andrew B. Mayfield、Jan B. Metternich、Adam H. Trotta、Eric N. Jacobsen
DOI:10.1021/jacs.0c00335
日期:2020.2.26
We report a new method for stereoselective O-furanosylation reactions promoted by a precisely tailored bis-thiourea hydrogen-bond-donor catalyst. Furanosyl donors outfitted with an anomeric dialkylphosphate leaving group undergo substitution with high anomeric selectivity, providing access to the challenging 1,2-cis substitution pattern with a range of alcohol acceptors. A variety of stereochemically distinct, benzyl-protected glycosyl donors were engaged successfully as substrates. Mechanistic studies support a stereospecific mechanism in which rate-determining substitution occurs from a catalyst-donor resting-state complex.
Studies on the synthesis of 1,2-cis pentofuranosides from S-glycofuranosyl dithiocarbamates, dithiocarbonates and phosphorodithioates
作者:Jadwiga Bogusiak、Wiesław Szeja
DOI:10.1016/s0008-6215(00)00220-2
日期:2001.1
The selectivity in the synthesis of 1,2-cis glycofuranosides from dithiocarbonates, dithiocarbamates and phosphorodithioates is improved by combined use of silver triflate and catalytic amount of hexamethylphosphoramide (HMPA) under mild conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.