Click Reaction in Carbohydrate Chemistry: Recent Developments and Future Perspective

The Identification of Perillyl Alcohol Glycosides with Improved Antiproliferative Activity

“…The scope of sugars selected for this study included representative pentoses ( d/l -arabinose, PG3 / PG28 ; l -ribose, PG17 ; d -xylose, PG22 ), hexoses ( d/l -glucose, PG1 / PG6 ; 3- O -methyl- d -glucose, PG4 ; l -rhamnose, PG32 ), azidosugars (6-deoxy-6-azido- d -glucose, PG2 ; 3-deoxy-3-azido- d -glucose, PG8 ; 4-deoxy-4-azido- d -glucose, PG9 ; 2-deoxy-2-azido- d -glucose, PG13 ; 4,6-deoxy-4,6-diazido- d -glucose, PG20 , 4-deoxy-4-azido- l -glucose, PG24 ; 4-deoxy-4-azido- d -xylose, PG34 ), fluorosugars (3-deoxy-3-fluoro- d -glucose, PG18 ; 4-deoxy-4-fluoro- d -glucose, PG21 ; 2-deoxy-2-fluoro- d -glucose, PG29 ; 2-deoxy-2-fluoro- d -mannose, PG30 ) N -acyl sugars ( N -acetyl- d -galactosamine, PG5 ; N -acetylmuramic acid, PG12 ; streptozocin, PG16 ; 3- N -decanoyl- d -glucosamine, PG23 ; 6- N -decanoyl- d -glucos amine, PG26 ; 3- N -allyloxylcarbonyl- d -glucosamine, PG27 ; 2- N -allyloxylcarbonyl- d -glucosamine, PG31 ; 6- N -allyloxylcarbonyl- d -glucosamine, PG33 ), an acid-bearing sugar ( d -glucuronic acid, PG25 ), and a dissacharide ( d -cellobiose, PG14 ) with a bias toward glucosides and acyl glucosides based upon the previously reported active glycosides ( 1a and 3a ). The inclusion of azidosugars served as a starting point for subsequent divergence via chemoselective modification [via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition] 35 , 36 or selective reduction to afford the corresponding aminosugar conjugates (Scheme 2 ). 30 , 32 , 37 − 39 A library of 34 distinct neoglycosides ( PG1 – PG34 ) were synthesized ( Figure S1 and Table S1 in Supporting Information ) in good to excellent yields (23–82%), with the β-anomer as predominate product in most cases, consistent with previous studies.…”

Stereoselective synthesis of tetrahydrofuranyl 1,2,3-triazolyl C-nucleoside analogues by ‘click’ chemistry and investigation of their biological activity

“…[38][39][40][41][42][43] The development of its very efficient copper catalyzed click reaction has made this reaction the most widely used method for the synthesis of 1,2,3-triazole. 39,40 Consequently in our present study we chose the copper catalyzed click reaction for the synthesis of the targeted 1,2,3-triazolyl C-nucleoside analogues of prototype-I and prototype-II ( Figure 2).…”

Cu–Al mixed oxide-catalysed multi-component synthesis of gluco- and allofuranose-linked 1,2,3-triazole derivatives

“…In this context, the two possible approaches are either to use a Cu(I) source directly into reaction with the presence of stabilizing ligands, or to generate it either by reduction of Cu(II) salts or by oxidation of elemental Cu. In situ generation of Cu(I) species using Cu(II) salts such as CuSO 4 or copper acetate is a more effective way, since these conditions allow reactions to be carried out without an inert atmosphere and it avoids the use of anhydrous solvents, endures aqueous conditions, and at the same time maintains a high Cu(I) concentration during the course of the reaction [ 23 ].…”