Imidazolium salts hydroxyethyl

Figure 3.68 Synthesis of a backside hydroxyethyl functionalised bis-imidazolium salt and its palladium(ll) complex.

Once the hydroxy functionalised imidazolium salt is formed, it can be deprotonised and reacted with various metal complexes to form (transition) metal carbene complexes. The hydroxy group ensures that the ligand can be coordinated even to metals that are normally reluctant to form stable carbene complexes. A good example is the deprotonation of a hydroxyethyl functionalised imidazolium salt with potassium hydride [36]. The potassium cation coordinates to the oxygen atom of the alkoxide sidechain and forms cubes as structural elements (see Figure 4.6). The carbene end then coordinates to the respective... 

The enantiopure hydroxyethyl functionalised imidazolium salts were successfully employed in the asymmetric conjugate addition of alkyls to cyclohexenone [46,48,49]. 

Other immobilized NHC-based rhodium catalysts targeted for screening in hydroformylation were synthesized by groups of Luis and Trzeciak (Scheme 2.166) [58, 59]. In the first step, Merrifield resin was functionalized to the corresponding bis(hydroxyethyl)amine derivatives. This material was converted into the corresponding dichlorides by chlorination with thionylchloride. Addition of an excess of 1-methylimidazol produced the immobilized bis-imidazolium salt. A... 

Zhou et al. have used the 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide for the microwave-assisted intramolecular Stetter reaction using imidazolium-type room temperature ionic liquids (RTILs) as solvents. The intramolecular Stetter reaction of ( )-methyl 4-(2-formylphenoxy) but-2-enoate was selected as a model to optimize the reaction conditions, using butylmethylimidazolium tetrafluoroborate [bmim]+[BF4]- as the solvent. It is known that salts of various heterocycles, including imidazolium salts, can also be used as catalysts. Therefore, the ionic liquids used as solvent is also able to function as a catalyst, even if it is less active than the usual thiazolium salts, and the yields of the desired product in that case are very poor. Subsequently, it was observed that when the quantity of thiazolium salt increased from 5 to 15 mol%, the yield improved accordingly to 96%. Under microwave irradiation, a variety of aromatic substrates undergo the intramolecular Stetter... 

Similar to the imidazolium ILs, very low solubility of the ammonium ILs was observed in alkanes. Eor example, the solubility of butyl(2-hydroxyethyl) dimethylammonium bromide, [(Ci)2C4HOC2N]Br, exhibited a simple eutectic system with immiscibility in the liquid phase in the IL mole fraction range from XjL = 0.02 to 0.70 [53] the other ammonium salt, (benzyl)dimethyl-alkylammonium nitrate, [Be(Ci)2C N] [NOJ showed very small solubility in the liquid phase in hexadecane and it was slightly better in hexane (immiscibility from XjL = 10 to 0.90) [99] for the ammonium salt with an alkane substituent only, didecyldimethylammonium nitrate, [(Cio)2(Q)2N][N03], the solubility in the liquid phase was better in hexane (immiscibility from XjL = 10 to 0.50) than in hexadecane, where the immiscibility was observed in the whole IL mole frachon [100]. In all systems with imidazolium and ammonium salts, an increase in the alkyl chain length of the alkane (solvent) resulted in a decrease of solubility. 

Similar good results of the separation of aromatic and aliphatic hydrocarbons were recently obtained with ethyl(2-hydroxyethyl)dimethylammonium Ws(trifluoromethylsulfonyl)imide, [(Cj)2C2HOC2N][Tf2N], at 298.15 K [160]. The separation of m-xylene from n-octane by extraction with [(Ci)2C2HOC2N] [TfjN] was observed with the distribution ration of 0.3 and selectivities of range 22-31. The other ammonium salt as [(Ci)2C4HOC2N][Bp4] or 1,3-dihexyl-oxymethyl-imidazolium tetrafluoroborate was not so successful in this separation [161]. 

BMIm]BF4 BMImCl [BMIm]PF6 CCS ecu [Choline] [Pro] 1 -butyl-3-methyl-imidazolium tetrafluoroborate 1 -butyl-3-methyl-imidazolium chloride 1 -butyl-3-methyl-imidazolium hexafluorophosphate CO2 capture and storage/sequestration CO2 capture and utilization (2-hydroxyethyl)-trimethyl-ammonium (iS )-2-pyrrolidine-carboxylic acid salt... 

EINECS/EEINCS 271-949-8 269-547-2 238-305-8 Synonyms IH-lmidazolium, 1-(carboxymethyl)-4,5-dihydro-1-(2-hydroxyethyl)-2-undecyl-, hydroxide, sodium salt Eauroamphoacetate Eauroamphoglycinate Sodium 1 (carboxymethyl)-4,5-dihydro-1 (or 3)-(2-hydroxyethyl)-2-undecyl-1 H-imidazolium hydroxide Classification Amphoteric organic compd. 

CAS 61791-52-4 EINECS/ELINCS 263-185-9 Synonyms Benzyl hydroxyethyl imidazolinium, cocoyl, chloride salt 2-(Cocoalkyl)-1-benzyl-1-(2-hydroxyethyl)-2-imidazolinium chloride Imidazolium compds., 1-benzyl-4,5-dihydro-1-(hydroxyethyl)-2-norcoco alkyl, chlorides Imidazolium compds., 4,5-dihydro-1-benzyl-1-... 

Dihydro-1-(2-hydroxyethyl)-3-(2-hydroxy-3-sulfonatopropyl)-2-undecyl-1H-imidazolium, monosodium salt. See Sodium lauroamphohydroxypropylsulfonate... 

Synonyms N-Cocamidoethyl-N-2-hydroxyethyl-N-carboxyethylglycine, sodium salt Cocoamphocarboxyglycinate Cocoamphodiacetate Imidazolium compds., 1-[2-(carboxymethoxy) ethyl]-1 -(carboxymethyl)-... 

Imidazolium compds., 1-(2-carboxyethyl)-4,5-dihydro-3-(hydroxyethyl)-2-norcoco alkyl, hydroxides, monosodium salts. See Sodium cocoamphopropionate... 

Isostearyl benzylimidonium chloride CAS 84625-60-5 EINECS/ELINCS 283-429-8 Synonyms 1 -Benzyl-4,5-dihydro-1 -(2-hydroxyethyl)-2-(15-methylhexadecyl)-1 H-imidazolium chloride 4,5-Dihydro-1-(2-hydroxyethyl)-2-isoheptadecyl-1 -phenylmethylimidazolium chloride Classification Quaternary ammonium salt Empirical C29H52N2O Cl Uses Antistat in cosmetics hair conditioner bactericide... 

Sodium lauroamphohydroxypropylsulfonate CAS 68039-23-6 EINECS/ELINCS 268-242-1 Synonyms 4,5-Dihydro-1 -(2-hydroxyethyl)-3-(2-hydroxy-3-sulfonatopropyl)-2-undecyl-1H-imidazolium, monosodium salt IH-lmidazolium, 4,5-dihydro1-(2-hydroxyethyl)-3-(2-hydroxy-3-sulfopropyl)-2-undecyl-, hydroxide, inner salt, monosodium salt Lauroamphohydroxypropylsulfonate Lauroamphopropylsulfonate ... 

Sodium taiiowamphoacetate Synonyms Glycine, N-(2-aminoethyl)-N-(2-hydroxyethyl)-, N-tallow acyl derive., monosodium salts Glycine, N-(2-hydroxyethyl)-N-(2-aminoethyl)-, N-tallow-acyl derive., sodium salts Imidazolium compds., 1-[2-(carboxymethoxy) ethyl]-4,5-dihydro-1 -(2-hydroxyethyl)-2-nortallow alkyl, hydroxides, inner salts Tallowamphoglycinate Classification Org. compd. 

According to Scheme 5, if IL has hydroxyl-alkyl moiety, it can have high activity for CO2 cydoaddition without additives, because of Lewis acidic nature of the OH group. Sun et al. [32] synthesized such task-spedfic ILs as hydroxyl-functionalized imidazolium and ammonium salts (Scheme 7). Among them, l-(2-hydroxyethyl)-3-methylimidazolium bromide ([HEMIm]Br) had the highest activity. It gave almost quantitative yield for the PC synthesis at 120°C and CO2 pressure of 2 MPa for 1 h, while non-modified IL of [EMIm]Br... 

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