Abstract
In order to investigate the potential of cyclodextrins for the preparation of block-like substituted polysaccharides, we submitted mixtures of heptakis[2,3,6-tri-O-methyl]-β-cyclodextrin (Me21-β-CD, 1) and heptakis[2,3,6-tri-O-methyl-d 3]-β-cyclodextrin ((Me-d 3)21-β-CD, 2) to cationic ring-opening polymerisation (CROP). Reactions were performed with BF3·OEt2, methyl triflate (MeOTf), and Et3OSbCl6. Products were compared with respect to their degree of polymerisation (DP) and the average block length (BL). Highest DP was observed with BF3·OEt2, while Et3OSbCl6 was the most active initiator. Average block length decreased from 14 in the early stage of product formation to about 2 due to competing chain transfer reaction. 1H NMR spectroscopy, GLC, GLC–MS, ESI-MS and MALDI-TOF-MS were applied for detailed investigations of side reactions. During incubation with BF3·OEt2, a stereroisomeric β-CD with one β-glucosidic linkage (Me21-β-CD6α1β, 3a (Me-d 3)21-β-CD6α 1β, 3b) is formed as an intermediate, while linear Me21- and (Me-d 3)21-maltoheptaose (4a/b) was detected in the early stage of the reaction promoted by MeOTf. In the case of Et3OSbCl6, both intermediates (3a/b, 4a/b) can be observed during the lag phase of polymerisation, but to a very low degree. End group analysis by GLC reveals that some alkyl exchange occurs at position 3 and 6 in the presence of Et3OSbCl6, and that polymerisation is also initiated by protons. Copolymerisation of heptakis[2,3,6-tri-O-benzyl]-β-cyclodextrin (Bn21-β-CD, 5) and Me21-β-CD (1) and subsequent debenzylation yielded a polymer of only 1,4-glcp-Me3- and 1,4-glcp-residues. Reactivity of Bn21-β-CD was significantly lower than of Me21-β-CD, resulting in higher average block length of 1,4-glcp-Me3-units.
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References
Adden R., Bösch A. and Mischnick P. (2004). Novel possibilities by cationic ring-opening polymerisation of cyclodextrin derivatives: preparation of a copolymer bearing block-like sequences of tri-O-methylglucosyl units. Macromol. Chem. Phys. 205:2072–2079
Andrews K.T., Klatt N., Adams Y., Mischnick P. and Schwartz-Albiez R. (2005). Inhibition of chondroitin-4-sulfate-specific adhesion of Plasmodium falciparum infected erythrocytes by sulfated polysaccharides. Infect. Immun. 73:4288–4294
Ciucanu I. and Kerek F. (1984). A simple and rapid method for the permethylation of carbohydrates. Carbohydr. Res. 131:209–217
Dicke R., Rahn K., Haack V. and Heinze Th. (2001). Starch derivatives of high degree of functionalization. Part 2. Determination of the functionalization pattern of p-toluenesulfonyl starch by peracylation and NMR spectroscopy. Carbohydr. Polym. 45:43–51
Evans A.G. and Meadows G.W. (1950). Polymerisation of isobutene by boron trifluoride. Trans. Farad. Soc. 46:327–331
Gohdes M. and Mischnick P. (1998). Determination of the substitution pattern in the polymer chain of cellulose sulfates. Carbohydr. Res. 309:109–115
Gonera A., Goclik V., Baum M. and Mischnick P. (2002). Preparation and structural characterisation of O-aminopropyl starch and amylose. Carbohydr. Res. 337:2263–2272
Higashimura T., Miki T., Okamura S. (1965). Kinetic studies of the solution polymerization of trioxane catalyzed by BF3+O(C2H5)2. I. The effect of the catalyst and the water concentration on the rate of polymerization. Bull. Chem. Soc. Jpn. 38:2067–2073
Johnson J.R. and Shankland N. (1985). Full assignment of the Proton and Carbon-13 NMR Spectra of 2,3,6-Tri-O-methyl- \(\beta\)-cyclodextrin. Tetrahedron 41:3147–3152
Kamitakahara H., Hori M. and Nakatsubo F. (1996). Substituent effect on ring-opening polymerization of regioselectively acylated \(\alpha\)-d-Glucopyranose-1,2,4-orthopivalat derivatives. Macromolecules 29:126–6131
Karakawa M., Mikawa Y., Kamitakahara H. and Nakatsubo F. (2002). Preparation of regioselectively methylated cellulose acetates and their 1H and 13C NMR spectroscopic analysis. J. Polym. Sci.: Part A: Polym. Chem. 40:4167–4179
Kern W., Chedron H. and Jaacks V. (1961). Polyoxymethylene. Angew. Chem. 73:177–186
Kern W., Jaacks V. (1960). Some kinetic effects in the polymerization of 1,3,5-Trioxane. J. Polym. Sci. 48 :399–404
Kikuzawa A., Kida T., Nakatsuji Y. and Akashi M. (2005). Short synthesis of skeleton-modified cyclodextrin derivatives with unique inclusion ability. J. Org. Chem. 70:1253–1261
Kobayashi S., Danda H., Saegusa T. (1974). Superacids and their derivatives. IV. Kinetic studies on the ring-opening polymerization of tetrahydrofuran initiated with ethyl trifluoromethanesulfonate by means of 19F and 1H nuclear magnetic resonance spectroscopy. Evidence for the oxonium–ester equilibrium of the propagating species. Macromolecules 7:415–420
Kondo T. and Gray D.G. (1991). The preparation of O-methyl- and O-ethyl-celluloses having controlled distribution of substituents. Carbohydr. Res. 220:173–183
Kondo T. (1993). Preparation of 6-O-alkylcelluloses. Carbohydr. Res. 238:231–240
Koschella A., Heinze Th. and Klemm D. (2001). First synthesis of 3-O functionalized cellulose ethers via 2,6-di-O-protected silyl cellulose. Macromol. Biosci. 1:49–54
Lecourt T., Mallet J.-M. and Sinaÿ P. (2003). An Efficient Preparation of 6I,IV Dihydroxy Permethylated \(\beta\)-Cyclodextrin. Carbohydr. Res. 338:2417–2419
Lecourt T., Herault A., Pearce A.J., Sollogoub M. and Sinaÿ P. (2004). Triisobutylaluminium and diisobutylaluminium hydride as molecular scalpels: the regioselective stripping of perbenzylated sugars and cyclodextrins. Chemistry 10:2960–2971
Liebert T. and Heinze Th. 1998. Cellulose Derivatives, Modification, Characterization and Nanostructures. In: Heinze Th. and Glasser W.G. (eds), ACS Symposium Series, Vol. 688, 61 pp
Mann G., Kunze J., Loth F. and Fink H.-P. (1998). Cellulose ethers with a block-like distribution of the substituents by structure-selective derivatization of cellulose. Polymer 39:3155–3165
Matyjaszewski K., Penczek S. (1974). Macroester, dbr Macroion equilibrium in the cationic polymerization of the THF observed directly by 300 MHz proton NMR. Polym. Sci., Polym. Chem. Ed. 12:1905–1912
Meerwein H. (1965). Oxoniumsalze. In: Müller E. (eds). Methoden der Organischen Chemie Band VI/3 Sauerstoff-Verbindungen Teil 3. Georg Thieme Verlag, Stuttgart, pp 328–363
Mischnick P., Heinrich J., Gohdes M., Wilke O. and Rogmann N. (2000). Structure analysis of 1,4-glucan derivatives. Macromol. Chem. Phys. 201:1985–1995
Mischnick P. and Kühn G. (1996). Correlation between reaction conditions and primary structure: model studies on methyl amylose. Carbohydr. Res. 290:199–207
Nakatsubo F., Kamitakahara H. and Hori M. (1996). Cationic ring-opening polymerization of 3,6-Di-O-benzyl- \(\alpha\)-d-glucose 1,2,4-orthopivalate and the first chemical synthesis of cellulose. J. Am. Chem. Soc. 118:1677–1681
Petzold K., Koschella A., Klemm D. and Heublein B. (2003). Silylation of cellulose and starch – selectivity, structure analysis, and subsequent reactions. Cellulose 10:251–269
Philipp B., Klemm D. and Wagenknecht W. (1995). Regioselektive Veresterung und Veretherung von Cellulose und Cellulosederivaten. Synthese regioselektiv substituierter Celluloseester. Das Papier 49:58–64
Sato T., Nakamura H., Ohno Y. (1990). Synthesis of 1,4-anhydro-2,3,6-tri-O-benzyl- \(\alpha\)-glucopyranose by cis-ring-closure of a glycosyl chloride. Carbohydr. Res. 199:31–35
Schaller J. and Heinze Th. (2005). Studies on the synthesis of 2,3-O-hydroxyalkyl ethers of cellulose. Macromol. Biosci. 5:58–63
Suzuki M., Numata O. and Shimazaki T. (2001). Cyclodextrin as a macrocyclic momomer: cationic ring-opening polymerisation of O-permethylcyclodextrins. Macromol. Rapid Commun. 22:1354–1357
Suzuki M. and Shimazaki T. (2003). Preparation of a unique glucan with large intervals in molecular weight distribution. Controlled ring-opening polymerization of O-permethylcyclodextrin. Org. Biomol. Chem. 1:604–608
Suzuki M., Numata O. and Shimazaki T. (2004). Novel cationic ring-opening polymerization of cyclodextrin: a uniform macrocyclic monomer with unique character. Macromol. Symp. 215:255–265
Sweet D.P., Shapiro R.H. and Albersheim P. (1975). Quantitative analysis by various g.l.c. response-factor therories for partially methylated and partially ethylated alditol acetates. Carbohydr. Res. 40:217–225
Yamashita Y., Okuda M. and Karahara H. (1968). Kinetic studies on the polymerisation of 1,3-dioxolane catalyzed by triethyloxonium-tetrafluoroborate. Makromolekulare Chemie 117:256–264
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This work is supported by Fonds der Chemischen Industrie (FCI) by means of a Doktorandenstipendium for Andreas Bösch.
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Bösch, A., Nimtz, M. & Mischnick, P. Mechanistic studies on cationic ring-opening polymerisation of cyclodextrin derivatives using various Lewis acids. Cellulose 13, 493–507 (2006). https://doi.org/10.1007/s10570-005-9029-9
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DOI: https://doi.org/10.1007/s10570-005-9029-9