A new protection group strategy for cellulose in an ionic liquid: simultaneous protection of two sites to yield 2,6-di-O-substituted mono-p-methoxytrityl cellulose

Ionic Liquids — Promising but Challenging Solvents for Homogeneous Derivatization of Cellulose

“…In addition to carboxymethyl cellulose, hydroxyethyl- and hydroxypropyl celluloses (entry 17 ) are among the most important ethers of cellulose that are employed in different commercial applications, e.g., as additive in paint, cement, and household products [ 88 ]. Hydroxyalkylation of cellulose with ethylene- and propylene oxide in the absence of bases has been studied in different ILs [ 64 , 65 ]. 1-Ethyl-3-methylimidazolium acetate (EMIMAc) has been described as the most suitable reaction medium because the acetate anion catalyzes ring opening of the oxiranes and the reaction with the polysaccharide.…”

“…Although not in any case explicitly mentioned, many of the homogeneous derivatization reactions discussed above have been performed not in pure ILs but in IL/co-solvent mixtures (see Table 1 ). Even in patented procedures of commercial interest, the beneficial use of co-solvents has been described [ 20 , 56 , 65 , 72 , 75 ]. The use of chloroform as non-polar co-solvent for trimethylsilylation of cellulose in ILs has already been described (see 3.3).…”

“…The use of chloroform as non-polar co-solvent for trimethylsilylation of cellulose in ILs has already been described (see 3.3). For dipolar aprotic co-solvents (DMSO, DMF) it has been demonstrated that the viscosity of cellulose/IL solutions decreases exponentially with the amount of co-solvent added [ 65 ]. Moreover, rheological studies have indicated that the conformation of cellulose dissolved in ILs is not impaired by the addition of DMSO [ 202 ].…”

Synthesis of Cellulose-2,3-bis(3,5-dimethylphenylcarbamate) in an Ionic Liquid and Its Chiral Separation Efficiency as Stationary Phase

“…Recently, Granström et al synthesized selectively protected 2,6-di- O -(4-methoxytrityl)cellulose in an ionic liquid of 1-allyl-3-methyl-imidazolium chloride (AMIMCl). It showed that AMIMCl not only functions as solvents for cellulose, but also be capable of increasing the reactivity [ 10 ]. Xu et al synthesized cellulose dehydroabietate by the O -acylation reaction of cellulose with dehydroabietic acid chloride using ionic liquid 1-butyl-3-methylimidazolium bromide as a solvent [ 11 ].…”

Derivatização de celulose sob condições homogêneas: cinética e mecanismo de acilação do biopolímero em LiCI/DMAC e liquídos iônicos/solventes apróticos dipolares

“…The degree of substitution (DS) depends on the various factors such as acylating reagent mole ratio to AGU, acylation time, use of catalyst and temperature but also on the dissolution state of cellulose Feng et al 2008). When cellulose is protected with 4-methoxytrityl in AlMeImCl, its reactivity is increased for further modification (Granstrom et al 2009). The synthetic procedure for different derivatives of cellulose such as ester, ethers, sulfonates, carbanilates, azides, hemiacetals, amines and deoxyderivatives has been shown below in Figure 1.33 (Pinkert et al 2009).…”