1- Allyl-3-methylimidazolium bromide

Prasad, K., Murakami, M., Kaneko, Y, Takada, A., Nakamura, Y, and Kadokawa, J. (2009]. Weak Gel of Chitin with an Ionic Liquid, 1-Allyl-3-Methylimidazolium Bromide, Int J. Biol Macromol, 45,221-225. 

However, only the limited investigations have been reported regarding the dissolution of chitin with ionic liquids including the author s study (Wu et al., 2008, Prasad et al., 2009, Qin et al., 2010, Wang et al., 2010), in which the author found that an ionic liquid, l-allyl-3-methylimidazolium bromide (AMlMBr) (Figure 3), dissolved or swelled chitin to form weak gel-like materials (ion gels) (Kadokawa, 2011, Kadokawa 2012). 

One of the important new directions in the study of addition reactions of organozinc compounds to aldehydes is the use of ionic liquids. Usually, application of these compounds in reactions with common organometallic reagents has a serious problem ionic solvents are usually reactive toward them, particularly Grignard and organolithium derivatives. It has been recently reported that carbonyl compounds react with allylzinc bromide formed in situ from allyl bromide and zinc in the ionic liquid 3-butyl-l-methylimidazolium tetrafluoroborate, [bmim][BF4].285 Another important finding is that the more reactive ZnEt2 alkylates aldehydes in a number of ionic liquids at room temperature.286 The best yields (up to 96%) were obtained in A-butylpyridinium tetrafluoroborate, [bpy][BF4] (Scheme 107). 

Indium-mediated Barbier-type coupling between carbonyl compounds and allyl halides has been revealed to proceed effectively in diverse reaction media. Even under solvent-free conditions, allylation works well, although no reaction is observed with benzyl bromide and a-halo carbonyl compounds.59 Various aldehydes react with allyl bromide mediated by indium in liquid carbon dioxide to give homoallylic alcohols (Scheme 1). In contrast to the corresponding neat allylation, the liquid C02-mediated reaction can allylate solid aldehydes successfully.60 Indium-mediated allylations of carbonyl compounds with allyl bromide proceed in room temperature ionic liquids. In [bmim][BF4] and [bmim][PF6] (bmin l-butyl-3-methylimidazolium), the desired homoallylic alcohols are formed with good levels of conversion.61 Homoallyllic alcohols are also prepared by the reaction of resin-bound aldehydes (Equation (l)).62... 

A broader exploitation of cellulose solubility in ionic liquids lies in modification of cellulose into more useful forms. Cellulose acetate is currently the most useful derivative of cellulose, with uses in photographic film, as a synthetic fibre and as a component of adhesives. Acetylation of cellulose has been carried out effectively in l-allyl-3-methylimidazolium chloride [Amim][Cl], [C4mim CI], [C2mim][Cl], l-butyl-2,3-dimethylimidazolium chloride [C4dmim][Cl] and l-allyl-2,3-dimethyl-imidazolium bromide [Admim][Br] [136, 159-162], The first report of cellulose acetylation in an ionic liquid involved a one-step reaction in [Amim][Cl] without catalyst, yielding cellulose acetate with a controllable degree of substitution [136], Yields of cellulose acetate of up to 86% have been obtained via reaction in [C4mim] [Cl] at 80 °C for 2 h [160],... 

Sn2 substitutions of allylic electrophiles, additions to oxo-carbenium ions, and many others. Suitable leaving groups in these substitution reactions include alkyl chlorides, bromides, iodides, mesylates, tosylates, and acetates. Often these processes are conducted under phase-transfer conditions, or require the use of 18-crown-6 to solubilize the salt and enhance the nucleophilicity of the acetate anion. The use of ionic solvents, such as butyl methylimidazolium tetrafluoroborate (Btnim BF4), has also proven useful. The following examples are representative (eqs 2-9). 

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