Synthesis of Randomly Substituted Anionic Cyclodextrins in Ball Milling.
A number of influencing factors mean that the random substitution of cyclodextrins (CD) in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent's hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill. Comparison with solution reactions, the solvent-free conditions strongly reduced the reagent hydrolysis and resulted in products of higher degree of substitution (DS) with more homogeneous DS distribution. The synthesis of anionic CD derivatives can be effectively performed under mechanochemical activation without significant changes to the substitution pattern but the DS distributions were considerably different from the products of solution syntheses.
Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy. ljicsinszky@gmail.com.
László
L
Jicsinszky
Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy. marina.caporaso@unito.it.
Marina
M
Caporaso
Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy. emanuela.calcio@unito.it.
Emanuela
E
Calcio Gaudino
Department of Chemistry, University of Turin, Via P. Giuria 7, 10125 Turin, Italy. cristina.giovannoli@unito.it.
Cristina
C
Giovannoli
Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy. laszlo.jicsinszky@unito.it.
Giancarlo
G
Cravotto
D000838:Anions / Q000138:chemical synthesis / Q000737:chemistry; D003505:Cyclodextrins / Q000737:chemistry*; D003912:Dextrins / Q000138:chemical synthesis* / Q000737:chemistry; D055772:Green Chemistry Technology; D006868:Hydrolysis; D012997:Solvents
D000838:Anions; D003505:Cyclodextrins; D003912:Dextrins; D012997:Solvents
anionic cyclodextrin; high-energy ball milling; random substitution; solvent-free reactions