- Effect of chain unsaturation on the self-association of tri- and tetraethylene glycol octyl ethers obtained by butadiene telomerization
-
2,7-Octadienyl ethers of tri- and tetraethylene glycol (C 8:2E3 and C8:2E4) have been synthesized by the atom-economical butadiene telomerization of the corresponding poly(ethylene glycols). On one hand, this synthetic path is attractive because it is expeditious and environmentally benign, and on the other hand, it provides unconventional amphiphiles for which the lipophilic chains possess two double bonds. These two unsaturations increase the global hydrophilicity of the compound, which is also highlighted by the modelization of the compounds using the conductor-like screening model for real solvents (COSMO-RS). The behavior of C8:2E3 and C8:2E4 in binary amphiphile/water and ternary amphiphile/oil/water systems is therefore greatly modified compared to that of the conventional fully saturated homologues (C 8E3 and C8E4) that are easily obtained after hydrogenation. This results in a lowered efficiency of the unsaturated compounds for oil solubilization. The usual Winsor-type microemulsion systems are formed, and for the same oil, the DLS investigation of the microstructure of the Winsor I microemulsion does not highlight any difference in the self-association between the unsaturated and saturated compounds.
- Lai, Jonathan,Molinier, Valerie,Sauthier, Mathieu,Moity, Laurianne,Castanet, Yves,Mortreux, Andre,Aubry, Jean-Marie
-
-
Read Online
- Chemo- and Regioselective Functionalization of Polyols through Catalytic C(sp3)-C(sp3) Kumada-Type Coupling of Cyclic Sulfate Esters
-
This contribution describes a copper-catalyzed, C(sp3)-C(sp3) cross-coupling reaction of cyclic sulfate esters, a distinct class of electrophilic derivatives of polyols, with alkyl Grignard reagents to afford functionalized alcohol products in good yields. The method is operationally simple and highlights the potential of cyclic sulfate esters as highly reactive substrates in catalytic, chemoselective polyol transformations.
- Ramírez-Contreras, Rodrigo,Morandi, Bill
-
p. 3718 - 3721
(2016/08/16)
-
- Combinatorial synthesis of PEG oligomer libraries
-
A simple chain-extending approach was established for the scale-up of the monoprotected monodisperse PEG diol materials. Reactions of THP-(OCH2CH2)n—OMs (n=4, 8, 12) with a large excess of commercially available H—(OCH2CH2)n—OH (n=1-4) under basic conditions led to THP-(OCH2CH2)n—OH (n=5-15). Similarly, Me-(OCH2CH2)n—OH (n=4-11, 13) were prepared from Me-(OCH2CH2)n—OMs (n=3, 7, 11). For the chain elongation steps, 40-80% yields were achieved through extraction purification. PEG oligomer libraries I and II were generated in 50-95% overall yields by alkylation or acylation of THP-(OCH2CH2)n—OH (n=1-15) followed by deprotection. Alkylation of Me-(OCH2CH2)n—OH (n=1-11, 13) with X—(CH2)m—CO2R (X=Br or OMs) and subsequent hydrolysis led to PEG oligomer library III in 30-60% overall yields. Combinatorial purification techniques were adapted to the larger-scale library synthesis. A total of 498 compounds, each with a weight of 2-5 g and a minimum purity of 90%, were synthesized.
- -
-
Page/Page column 9
(2010/02/15)
-
- Omega-hydrofluoroalkyl ethers, precursor carboxylic acids and derivatives thereof, and their preparation and application
-
Normally liquid, omega-hydrofluoroalkyl ether compounds (and selected mixtures thereof) have a saturated perfluoroaliphatic chain of carbon atoms interrupted by one or more ether oxygen atoms. The compounds can be prepare, e.g. by decarboxylation of the corresponding fluoroalkyl ether carboxylic acids and are useful, e.g., in cleaning and drying applications.
- -
-
-
- Process for preventing consolidation of p-dichlorobenzene
-
A triethylene glycol derivative is added to p-dichlorobenzene so as to prevent consolidation and improve flowability of p-dichlorobenzene.
- -
-
-
- Topical mosquito repellents VII: Alkyl triethylene glycol monoethers
-
Normal and branched chain aliphatic monoethers of triethylene glycol are effective topical mosquito repellents. In terms of duration of protection, they are generally superior to the corresponding diethylene glycol analogs, and some are superior to diethyltoluamide. The n heptyl monoether of triethylene glycol affords double the protection time of diethyltoluamide under controlled laboratory conditions, and appears to be a useful new mosquito repellent.
- Johnson,DeGraw,Engstrom,Skinner,Brown,Skidmore,Maibach
-
p. 693 - 695
(2007/10/05)
-
