258349-79-0Relevant academic research and scientific papers
New macrocycles incorporating glycolipids via copper-catalyzed triazole coupling
Kareem, Nuha S.,Mohammed, Shaymaa A.,Abed, May Jaleel,Aneed, Asaad H.,Kamal, Hayder M.,Zahid, N. Idayu,Sabah, Karem J.
, p. 1 - 17 (2022/03/03)
A series of new macrocycles based on alkyl glycosides derived from D-glucose and D-galactose was synthesized. The macrocycles were easily obtained by the reaction of dialkynyl derivatives with diazides via copper-catlyzed 1,3-cycloaddition reaction. Simple protecting group strategies were applied to obtain the vicinal dihydroxy derivatives, followed by Williamson etherification with propargyl bromides to get the dialkynyl derivatives. These derivatives were subjected to 1,3-Hüisgen triazole coupling with diazides furnishing the macrocycles in good yields. The 1,3-Hüisgen reaction used to build these macrocycles was investigated thoroughly with respect to reaction time, catalysts, solvents, and temperature for optimum macrocyclisation.
Synthesis of new chiral macrocycles-based glycolipids and its application in asymmetric Michael addition
Sabah, Karem J.,Zahid, N. Idayu,Hashim, Rauzah
, p. 2653 - 2667 (2021/03/19)
A series of new mix aza- and thia-macrocyclic glycolipids (9, 10, 16 and 17) have been synthesized and their enantiomeric selectivity was studied. The synthesis of the macrocycles involved a simple protection of two hydroxyl groups of the glycolipids followed by building up the mix-heteroatom macrocyclic in simple sequences. The macrocycles and previously investigated analogues (18, 19, 20 and 21) have been applied as phase transfer catalysts in the enantioselective Michael addition of 2-nitropropane to chalcone and showed good-to-excellent enantiomer excess (ee). Among the catalysts, the galactose aza-crown ether-based glycolipid 21 proved to be the most effective with 90% ee. Graphic abstract: [Figure not available: see fulltext.]
Novel crown ethers on glucose based glycolipids
Sabah, Karem,Heidelberg, Thorsten,Hashim, Rauzah
scheme or table, p. 891 - 896 (2011/05/28)
A series of crown ethers involving lauryl glucoside were synthesized and their assembly behavior in water was studied. The synthesis applied a simple protection scheme based on benzylidenation for the glycolipid, and cation templating for the macrocycle. A sequential build-up of the crown ether by bis-hydroxylethylation of the glucoside followed by reaction with di-, tri-, or tetraethylene glycol ditosylate provided better yields of the macrocycle compared to a single step cyclization with tetraethylene glycole ditosylate. The macrocycles containing up to six oxygens showed significantly higher affinity for sodium than for potassium, while more effective potassium complexation was found for the 21-crown-7 compound. The ion binding affinity leads to a slight but significant increase of the CMC of the crown ether containing surfactant in water upon the addition of sodium electrolyte.
Interactions of hydroxy compounds and sugars with anions
Coteron, Jose Miguel,Hacket, Frank,Schneider, Hans-Joerg
, p. 1429 - 1435 (2007/10/03)
Complexations of aliphatic monohydroxy compounds, of trans-1,2 cyclohexanediol, and of several glucose and galactose derivatives with two to four free hydroxy groups are measured in chloroform with peralkylammonium salts containing different anions. It is shown that NMR titrations with up to four different OH signals as well as with some CH signals allow accurate and consistent calculation of equilibrium constants K and complexation induced shifts (CIS). The anions used generally show an increasing affinity in the order iodide 3 M-1 for 1-dodecyl glucose or galactose compounds. The observed CIS and K values agree with the formation of 3 different 1:1 complexes of similar stability for the phosphate receptor, with binding one anion between the 2-, 3-, 4-, and 6-OH groups of the glucoside, or only one 1:1 complex in the interaction of halides with sugars. Vicinal 3JHOCH coupling constants are analyzed before and after complexation and provide insight into the hydrogen bond network of the sugar derivatives.
