**2.5 Primary alcohol-functionalized ionic liquid**

Further, polyethylene glycol was used for functionalization of imidazoliumbased ionic liquid and studied for SN2 reactions. Kim et al. [11] synthesised hexaehtylene glycol *chain IL*s [hexaehtylene glycol-im][OMs] and [dihexaehtylene glycol-im][OMs] (hexaehtylene glycol-im = 1-hexaethylene glycolic 3-methylimidazolium cation; dihexaehtylene glycol-im = 1,3-dihexaethylene glycolic imidazolium cation; OMs = mesylate anion) by using simple organic reaction process as shown in **Figure 6** [12]. Synthesized various lengths of oligoether was have better chelation efficiency with metal cation due to presence of oxygen atoms intraction from both side of imidazolium IL.

**211**

**Figure 6.**

*bis-glycol chain substituted IL.*

*Protic Reaction Media for Nucleophilic Substitution Reactions*

philic fluorination by using salts of metal nucleophiles (**Figure 7**).

synthesised using a protic ionic liquid as shown in **Figure 8**.

**2.6 Di-***tert***-alcohol-functionalized dicationic ionic liquid**

The author described the role of all functional moieties of ionic liquid in nucleo-

The application of di-functional polyether chain-substituted imidazolium ionic liquids in the synthesis of various bioactive molecules such as fluoro-flumazenil, fluoropropyl ciprofloxacin, etc., which are useful in molecular probes for PET, is

The same research group developed another dicationic protic ionic liquid for substitution reactions. A task-specific hexaethylene glycol bridged bis-cationic ionic liquid (BFIL) such as bis(2-hydroxy-2-methyl-n-propylimidazolium) dimesyl-

The use of bis-functionalized ionic liquid (BFIL) enhances the substitution reaction rate compared to conventional ionic liquid as well as mono-functionalized protic ionic liquid due to the higher activity of BFIL by the additional dicationic moieties compared with the mono-cationic ionic liquid methods. The author found that the hexaethylene glycol moiety of these hexaehtylene glycol chain-functionalized ILs enhances the reactivity of alkali metal fluorides by two effects; one is chelation effect with alkali metal cations, allowing the fluoride to become necked, and the other is the flexible fluoride influence by flexible H-bonding between the hydroxyl groups of BFIL, t-alcohol medium and nucleophile. In the case of t-alcohol-functionalized BFIL, the t-alcohol moiety showed selectively flexible H-bonding in the process. Subsequently,

*Synthesis of polar-aprotic glycol substituted imidazolium ionic liquids. A) mono-glycol chain substituted IL, B)* 

substitution reactions using an alkali metal nucleophiles was investigated [13]. They also compared their activities with a variety of mono-cationic ILs and found that the hexaehtylene glycol chain-functionalized IL more effectively enhanced the reactivity of KX compared with the *tert*-alcohol-functionalized IL hexaehtylene

OHIM) was prepared, and its role in nucleophilic

*DOI: http://dx.doi.org/10.5772/intechopen.91395*

ate (hexaehtylene glycol chain-Dt

OHIM (**Figure 9**).

glycol chain-Dt

*Photophysics, Photochemical and Substitution Reactions - Recent Advances*

interactions; as a result, nucleophilicity of chloride increases dramatically. Thus, the protic EAN is found as a suitable reaction solvent for nucleophilic bimolecular substitution reactions. These experiments demonstrate the flexibility of this kind of nanoreactor system to alter the polar protic solvent trapping and its impact on

Song et al. observed that the alcohol contained polyethylene glycol as good reaction media for various nucleophilic substitution reactions [10]. Achiral polyether derivatives have shown dramatic acceleration in the SN2 reactions by the simultaneous activation of both the nucleophile and electrophile sites of the leaving group. They also studied desiylation and found that bis-terminal ▬OH group plays a key role that the desilylative kinetic resolution is successively done of the silyl ethers of

Further, polyethylene glycol was used for functionalization of imidazolium-

hexaehtylene glycol *chain IL*s [hexaehtylene glycol-im][OMs] and [dihexaehtylene glycol-im][OMs] (hexaehtylene glycol-im = 1-hexaethylene glycolic 3-methylimidazolium cation; dihexaehtylene glycol-im = 1,3-dihexaethylene glycolic imidazolium cation; OMs = mesylate anion) by using simple organic reaction process as shown in **Figure 6** [12]. Synthesized various lengths of oligoether was have better chelation efficiency with metal cation due to presence of oxygen atoms intraction

based ionic liquid and studied for SN2 reactions. Kim et al. [11] synthesised

**210**

the rate of the reaction.

**Figure 5.**

**Figure 3.**

**Figure 4.**

**2.4 Polar protic solvent glycol**

*Structures of ethylammonium nitrate (EAN).*

*Nucleophilic fluorination by protic ionic liquid 1a.*

*Nucleophilic fluorination on secondary mesylate by using CsF and 1a.*

racemic secondary alcohols.

from both side of imidazolium IL.

**2.5 Primary alcohol-functionalized ionic liquid**

The author described the role of all functional moieties of ionic liquid in nucleophilic fluorination by using salts of metal nucleophiles (**Figure 7**).

The application of di-functional polyether chain-substituted imidazolium ionic liquids in the synthesis of various bioactive molecules such as fluoro-flumazenil, fluoropropyl ciprofloxacin, etc., which are useful in molecular probes for PET, is synthesised using a protic ionic liquid as shown in **Figure 8**.
