- A mechanism of alkali metal carbonates catalysing the synthesis of β-hydroxyethyl sulfide with mercaptan and ethylene carbonate
-
The reaction of β-hydroxyethylation is essential to the current practice of organic chemistry. Here, we proposed a new and green route to synthesize 2-hydroxyethyl n-alkyl sulfide with n-alkyl mercaptan and ethylene carbonate (EC) in the presence of alkali carbonates as catalysts and revealed the mechanism by experiments and theoretical calculations. The reaction reported proceeds rapidly with high yields when it is performed at 120 °C and the catalytic loading is ~1 mol%. This protocol is applicable to other mercaptans to synthesize the corresponding β-hydroxyethyl sulfide. Density functional theory-based calculations show the energy profile for the reaction pathway. The rate-determining step is the ring-opening of EC. A negatively charged O atom of alkali carbonates approaches the S atom of -SH under the influence of hydrogen bonds. An activated S atom that carries more negative charge serves as a nucleophilic reagent and assists in the ring-opening of EC by reducing the Mayer bond orders of the C1-O1 bond in EC. Alkali cations also contribute to the C1-O1 bond cleavage. The energy barrier for the ring-opening of EC decreases with the decrease of electronegativity of alkali cations. Subsequent transference of a H atom leads to the formation of β-hydroxyethyl sulfide, the dissociation of CO2 and the reduction of K2CO3
- Liu, Dongliang,Thomas, Tiju,Gong, Hong,Li, Fei,Li, Qiang,Song, Lijuan,Azhagan, Tamil,Jiang, Heng,Yang, Minghui
-
p. 9367 - 9374
(2019/11/13)
-
- Chemical Structure and Thermodynamics of Amphiphile Solutions. 1. Solubility of Alkylthiooligooxyethylene Glycols in Water
-
Solubilities of individual alkylthiooligooxyethylene glycols CnH2n+1SCH2CH2(OCH2CH2)zOH (alkyl: n-C4H9, ..., n-C9H19; and z = 0, ..., 3) in water at 298.15 K have been determined.A quantitative correlation has been found between the standard free energy for transfer from aqueous solution to pure liquid phase, ΔGot, and the structure of the studied sulfides and of oligooxyethylenated alcohols as well by using the appropriate multiple regression equation.It has been found that the thioethylene group, -SCH2CH2-, is hydrophobic.The standard free energy contribution, ΔGot, is -3.4 kJ mol-1.The interaction between methylene groups, -CH2-, of the hydrocarbon chain and the -OCH2CH2- groups of the oligooxyethylene chain is statistically significant and has an influence on the total value of ΔGot.Furthermore, the ΔGot and ΔGot are not constant.For the sulfides studied, ΔGot increases linearly with hydrocarbon chain length.For example, ΔGot for the series of butyl and nonyl derivatives is +0.24 and +0.81 kJ mol-1, respectively.The ΔGot for the series of alkyl-2-hydroxyethyl sulfides (z=0) and alkylthiotetraoxyethylene glycol (z=3) is -3.43 and -3.10 kJ mol-1, and the ΔGot and ΔGot for the group of oxyethylenated alcohols are +0.53 and -3.13 kJ mol-1, respectively.
- Sokolowski, Adam
-
p. 8223 - 8226
(2007/10/02)
-
- REACTIONS OF OXIRANES WITH ALKYLTHIOLS
-
Alkyl-2-hydroxyalkyl sulfides and their oxyalkylenated adducts were obtained in the reaction of oxirane or methyloxirane with C4-C12 alkylthiols in presence of basic or acidic catalysts.The sulfides were further oxidized to sulfoxides and sulfones.
- Chlebicki, Jan,Cichacz, Zbigniew
-
p. 485 - 494
(2007/10/02)
-