Synthesis of a new hydrophilic poly(ethylene glycol)-ionic liquid and its application in peptide synthesis

Abstract

The synthesis of a new hydrophilic ammonium-based poly(ethylene glycol)-ionic liquid (PEG-IL) is reported; the structure was assigned by NMR ((1)H, (13)C) and MALDI mass spectrometry. The viscosity and thermal stability were also studied, as well as its polarity. Its application as an alternative solvent in the synthesis of dipeptides under microwave irradiation is also described.

Synthesis of poly(ethylene glycol) functionalized star-shaped tricationic imidazolium based ionic liquid

“…It was found that STIIL was miscible in most of the organic solvents we used, such as CH 2 Cl 2 , EtOAc, CH 3 CN, DMF, CH 3 OH and H 2 O. However, it found out to form a biphasic system and immiscible in petroleum ether (PE) and diethyl ether (Et 2 O), which was coincidence with the miscibility of a hydrophilic ammonium-based poly(ethylene glycol)-ionic liquid (PEG-IL) reported by Colacino et al [44] . Interestingly, compared the ionic liquid immiscible or partially miscible in ethyl acetate with previously reported literature [45] , the STIIL reported here could be well miscible in ethyl acetate.…”

“…Interestingly, compared the ionic liquid immiscible or partially miscible in ethyl acetate with previously reported literature [45] , the STIIL reported here could be well miscible in ethyl acetate. This difference should be ascribed to the presence of three PEG arms in STIIL, which enhanced the solubility of STIIL in ethyl acetate [44] .…”

“…The final products could self-assemble to form a solvent-free ionic gel without assistance, and had been tested to possess a potential application as an electrolyte in dye-sensitized solar cells. In addition, Colacino et al [44] reported the synthesis of a hydrophilic ammonium based PEG-ionic liquid, which could be used in the application of peptide coupling under microwave activation. The lightspot of this work is that two PEG chains grafted onto the center ammonium cation could lead to a battery of outstanding physicochemical properties compared with the traditional one PEG tail attached ionic liquid, and resulted in the potential usage in some special situations.…”

Poly(ethylene glycol)‐Based Ionic Liquids: Properties and Uses as Alternative Solvents in Organic Synthesis and Catalysis

“…Similarly, mono-[mPEG 350 [Br] (6) ammonium-based IL PEG s were synthesized from brominated PEG methyl ether and gaseous N,N-dimethylamine or N,N,N',N'-tetramethylethylenediamine (TMEDA), respectively, in an alcoholic solvent [32] (Scheme 2). Nucleophilic substitution with alkyl imidazoles on PEG methane sulfonate derivatives in solution or in neat conditions afforded the corresponding water-soluble butylimidazolium [mPEG 350 BuIm][PF 6 ] (7 a) [27] [33] (R 2 = Me, nPr, iPr) after chromatographic purification, and oligoether [PEG 300 MeIm][OMs] (7 c) [34] after precipitation/filtration workup from diethyl ether.…”

Title Pages

“…Also note Danishefsky′s new peptide ligation 49 , and a new medium for peptide coupling 50 . To close, a new one-pot, Fischer-inspired indole synthesis from ar.…”