Fluoride-Promoted Esterification (FPE) Chemistry: A Robust Route to Bis-MPA Dendrons and Their Postfunctionalization
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
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Academic Editor: Ashok Kakkar
Molecules 2016, 21(3), 366; https://doi.org/10.3390/molecules21030366
Received: 19 February 2016 / Revised: 10 March 2016 / Accepted: 10 March 2016 / Published: 17 March 2016
(This article belongs to the Special Issue Functional Dendrimers)
Bifunctional dendrons based on 2,2-bis(methylol)propionic acid (bis-MPA) are highly desirable scaffolds for biomedical applications. This is due to their flawless nature and large and exact number of functional groups as well as being biodegradable and biocompatible. Herein, we describe a facile divergent growth approach to their synthesis from monobenzylated tetraethylene glycol and post functionalization utilizing fluoride-promoted esterification (FPE) chemistry protocols. The scaffolds, presenting selectively deprotectable hydroxyls in the periphery and at the focal point, were isolated on a multigram scale with excellent purity up to the fourth generation dendron with a molecular weight of 2346 Da in seven reactions with a total yield of 50%. The third generation dendron was used as a model compound to demonstrate its functionalizability. Selective deprotection of the dendron’s focal point was achieved with an outstanding yield of 94%, and biotin as well as azido functionalities were introduced to its focal point and periphery, respectively, through FPE chemistry. Bulky disperse red dyes were clicked through CuAAC to the dendron’s azido groups, giving a biotinylated dendron with multivalent dyes with a molecular weight of 6252 Da in a total yield of 37% in five reactions with an average yield of 82% starting from the third generation focally and peripherally protected dendron. FPE chemistry proved to be a superb improvement over previous protocols towards bis-MPA dendrons as high purity and yields were obtained with less toxic solvents and greatly improved monomer utilization.
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Keywords:
dendron; dendritic polymers; polyesters; bis-MPA; FPE chemistry; carbonyl diimidazole; biotin; CuAAC click chemistry
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MDPI and ACS Style
Stenström, P.; Andrén, O.C.J.; Malkoch, M. Fluoride-Promoted Esterification (FPE) Chemistry: A Robust Route to Bis-MPA Dendrons and Their Postfunctionalization. Molecules 2016, 21, 366. https://doi.org/10.3390/molecules21030366
AMA Style
Stenström P, Andrén OCJ, Malkoch M. Fluoride-Promoted Esterification (FPE) Chemistry: A Robust Route to Bis-MPA Dendrons and Their Postfunctionalization. Molecules. 2016; 21(3):366. https://doi.org/10.3390/molecules21030366
Chicago/Turabian StyleStenström, Patrik; Andrén, Oliver C.J.; Malkoch, Michael. 2016. "Fluoride-Promoted Esterification (FPE) Chemistry: A Robust Route to Bis-MPA Dendrons and Their Postfunctionalization" Molecules 21, no. 3: 366. https://doi.org/10.3390/molecules21030366
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