Highly regioselective and stereoselective synthesis of C-Aryl glycosides <i>via</i> nickel-catalyzed <i>ortho</i>-C–H glycosylation of 8-aminoquinoline benzamides
C-Arylglycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr–H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential. Mechanistic studies indicate that C–H activation could be the rate-determining
C-芳基糖苷作为候选药物具有很高的价值。本文描述了一种新颖且经济高效的镍催化邻-C Ar -H 糖基化反应,具有高区域选择性和优异的 α-选择性。该方法与各种糖苷表现出良好的官能团相容性,显示出其合成潜力。机理研究表明 C-H 激活可能是速率决定步骤。
Palladium-Catalyzed <i>ortho</i>-C–H Glycosylation/<i>ipso</i>-Alkenylation of Aryl Iodides
This report describes the first example of palladium-catalyzed ortho-C–H glycosylation/ipso-alkenylation of aryliodides, and the easily accessible glycosyl chlorides are used as a glycosylation reagent. The reaction is compatible with the functional groups of the substrates, and a series of C-aryl glycosides have been synthesized in good to excellent yield and with excellent diastereoselectivity.
In this work, we describe a Catellani-type C-H glycosylation to provide rapid access to various highly decorated α-C-(hetero)aryl glycosides in a modular and stereoselective manner (>90 examples). The termination step is flexible, which is demonstrated by ipso-Heck reaction, hydrogenation, Suzuki coupling, and Sonogashira coupling. Application of this methodology has been showcased by preparing gl
作者:Yongho Park、Kaid C. Harper、Nadine Kuhl、Eugene E. Kwan、Richard Y. Liu、Eric N. Jacobsen
DOI:10.1126/science.aal1875
日期:2017.1.13
challenges to their synthesis. In particular, stereochemical outcomes in glycosylationreactions are highly dependent on the steric and electronic properties of coupling partners; thus, carbohydrate synthesis is not easily predictable. Here we report the discovery of a macrocyclic bis-thiourea derivative that catalyzes stereospecific invertive substitution pathways of glycosyl chlorides. The utility of
New Method for Regioselective Glycosylation Employing Saccharide Oxyanions
作者:Martin Matwiejuk、Joachim Thiem
DOI:10.1002/ejoc.201100861
日期:2011.10
As an alternative concept for glycosylation, the prior activation of acceptor hydroxy groups for selective glycosidic bond formation, was investigated to give complex oligosaccharides. Oxyanions obtained from partially protected saccharides were glycosylated by employing glycopyranosyl halides, and the regiochemical results were studied. Initially, partially methylated methyl-α-D-glucopyranosides were