Synthesis of reverse glycosyl fluorides via organophotocatalytic decarboxylative fluorination of uronic acids

Abstract

An efficient protocol for organophotocatalytic synthesis of reverse glycosyl fluorides (RGFs) is established relying on 9-mesityl-10-methyl-acridinium (Mes-Acr+)-mediated oxidative decarboxylative fluorination of uronic acids. Both pentofuranoid and hexopyranoid uronic acids are...

Transformations of carbohydrate derivatives enabled by photocatalysis and visible light photochemistry

“…Reversed glycosyl fluorides have been synthesized by decarboxylative fluorinations of uronic acid derivatives in the presence of an acridinium photocatalyst ( Scheme 40 ). 94 Li and co-workers found that disarmed (benzoyl-protected) substrates tended to give lower yields of the reversed glycosyl fluorides than their armed, benzyl-protected counterparts. Nucleoside analogs arising from fluorination at C4′ were also accessed using this approach.…”

Drug Discovery Based on Fluorine-Containing Glycomimetics

“…In a recent development, Li’s group established a protocol for the organophotocatalytic synthesis of glycosyl fluorides without the addition of silver species. This method relies on 9-mesityl-10-methyl-acridinium (Mes-Acr + )-mediated oxidative decarboxylative fluorination of uronic acids [ 67 ] ( Figure 10 b). The potential of this method is promising in the synthesis of fluorinated nucleosides.…”

Access to Reverse Glycosyl Azides and Rare Sugar-Based Glycosyl Azides via Radical Decarboxylative Azidation: Divergent Synthesis of 4'-C-Azidonucleosides as Potential Antiviral Agents

“…These methods face challenges in preparing glycosyl azides of rare sugars due to the poor accessibility of the corresponding starting sugar materials. In continuation of our interest in radical functionalization of uronic acids, we describe herein a novel approach to access structurally diverse RGAs and rare sugar-based glycosyl azides through radical decarboxylative azidation of uronic acids. The transformation is efficiently catalyzed by Ag 2 CO 3 , using K 2 S 2 O 8 as the sacrificial oxidant and 3-pyridinesulfonyl azide (3-PySO 2 N 3 ) as the azidating source.…”

“…Building on the success of radical decarboxylative azidation of aliphatic carboxylic acids and our previous work on decarboxylative functionalization of uronic acids, we initiated our studies using glucuronic acid 4a as a model substrate. Through systematic evaluation of various reaction parameters (detailed in Supporting Information (SI), Table S1), we identified the optimal reaction conditions as follows: 4a (1.0 equiv), 3-PySO 2 N 3 5 (3.0 equiv) as azidating agent, Ag 2 CO 3 (0.15 equiv) as catalyst, K 2 S 2 O 8 (2.0 equiv) as the terminal oxidant, and stirring at 80 °C for 1 h in a mixture of MeCN/H 2 O (v/v, 1:1).…”