5735-88-6Relevant academic research and scientific papers
Pickering emulsions assisted synthesis of fatty acetal over phenyl sulfonic groups grafted on activated charcoal
Clacens, Jean-Marc,Corbet, Matthieu,Marion, Philippe,Richard, Frédéric,Xu, Minrui
, (2020)
Activated charcoal Darco? KB-G, was functionalized with phenyl sulfonic groups (Ph-SO3H) by surface modification in acidic aqueous media under mild conditions (25 °C, Patm). The formation of new C[sbnd]C covalent bonds was confirmed by both TGA and XPS. The functionalized amphiphilic solids were also characterized by nitrogen adsorption-desorption, SEM, IR and Raman spectroscopy. The reference solid Darco-0.50ASFL stabilized dodecyl aldehyde/ethylene glycol by Pickering emulsions and demonstrated both good activity and selectivity in a solvent-free biphasic acetalization. Kinetic studies of the formation of hemiacetal and acetal were investigated by monitoring the progress of the reaction by HPLC. Experimental kinetic profiles of dodecyl aldehyde, hemiacetal and acetal were compared to model kinetic profiles. The recycling of Darco-0.50ASFL was also studied by performing five consecutive catalytic runs without regeneration of the catalyst.
Aquivion-carbon composites via hydrothermal carbonization: Amphiphilic catalysts for solvent-free biphasic acetalization
Fang, Wenhao,Fan, Zhaoyu,Shi, Hui,Wang, Sheng,Shen, Wei,Xu, Hualong,Clacens, Jean-Marc,De Campo, Floryan,Liebens, Armin,Pera-Titus, Marc
, p. 4380 - 4385 (2016)
One-pot hydrothermal carbonization of polysaccharides (i.e. guar gum or cellulose) with Aquivion perfluorosulfonic superacid at 180 °C produced new amphiphilic Aquivion-carbon composites. The materials stabilized dodecyl aldehyde/ethyleneglycol Pickering emulsions, and thus efficiently catalyzed the solvent-free biphasic acetalization reaction under moderate conditions with excellent reusability.
Tunable catalysts for solvent-free biphasic systems: Pickering interfacial catalysts over amphiphilic silica nanoparticles
Zhou, Wen-Juan,Fang, Lin,Fan, Zhaoyu,Albela, Belén,Bonneviot, Laurent,De Campo, Floryan,Pera-Titus, Marc,Clacens, Jean-Marc
supporting information, p. 4869 - 4872 (2014/04/17)
Stabilization of oil/oil Pickering emulsions using robust and recyclable catalytic amphiphilic silica nanoparticles bearing alkyl and propylsulfonic acid groups allows fast and efficient solvent-free acetalization of immiscible long-chain fatty aldehydes with ethylene glycol.
Direct conversion of acetals to esters with high regioselectivity via O,P-acetals
Maegawa, Tomohiro,Otake, Kazuki,Goto, Akihiro,Fujioka, Hiromichi
supporting information; experimental part, p. 5648 - 5651 (2011/09/15)
A new direct conversion of O,O-acetals to esters via O,P-acetal intermediates was developed. The regioselective cleavage of unsymmetrical cyclic acetals occurred to give the more crowded esters as single isomers.
Towards the rational design of palladium-N-heterocyclic carbene catalysts by a combined experimental and computational approach
O'Brien, Christopher J.,Kantchev, Eric Assen B.,Chass, Gregory A.,Hadei, Niloufar,Hopkinson, Alan C.,Organ, Michael G.,Setiadi, David H.,Tang, Ting-Hua,Fang, De-Cai
, p. 9723 - 9735 (2007/10/03)
A combined experimental and computational approach towards the development of Pd-NHC catalysts is described. A range of benzimidazolylidinium ligands incorporating electron-rich and electron-poor substituents were prepared and evaluated in the Suzuki reaction. The most electron-rich ligand showed the highest catalytic activity. Based on this information, the first alkyl-alkyl Negishi cross-coupling reaction protocol was developed. Evaluation of N,N′-diaryl-(4,5-dihydro)imidazolylilidinium ligands showed a strong dependence on the steric topography around the metal centre. A computational study of the most active ligand in the Negishi reaction, its Pd(0) and PdCl 2-complexes and related structures were modelled at the B3LYP/DZVP and HF/3-21G levels of theory. The potential energy hypersurfaces flattened with increase in ligand size. Binding energies were computed for carbene/Pd(0) adducts (in the range ~31-40 kcal mol-1), roughly double that for PH3 (~16 kcal mol-1). Weak intramolecular interactions were found using AIM analyses.
The first Negishi cross-coupling reaction of two alkyl centers utilizing a Pd-N-heterocyclic carbene (NHC) catalyst
Hadei, Niloufar,Kantchev, Eric Assen B.,O'Brien, Christopher J.,Organ, Michael G.
, p. 3805 - 3807 (2007/10/03)
(Chemical Equation Presented) The development of an NHC-based system capable of cross-coupling sp3-sp3 centers in high yield has been a long-standing challenge. This communication describes the use of a Pd-NHC catalytic system that achieves room-temperature Negishi cross-couplings of unactivated, primary bromides and alkyl organozinc reagents with a variety of functionality.
Room-temperature Negishi cross-coupling of unactivated alkyl bromides with alkyl organozinc reagents utilizing a Pd/N-heterocyclic carbene catalyst
Hadei, Niloufar,Kantchev, Eric Assen B.,O'Brien, Christopher J.,Organ, Michael G.
, p. 8503 - 8507 (2007/10/03)
A high-yielding cross-coupling reaction of unactivated alkyl bromides possessing β-hydrogens with alkylzinc halides utilizing a Pd/N-heterocyclic carbene (NHC) catalyst at room temperature is described. A variety of Pd sources, Pd2(dba)3, Pd(OAc)2, or PdBr 2, with the commercially available ligand precursor 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (IPr·HCl) successfully coupled 1-bromo-3-phenylpropane with n-butylzinc bromide in THF/NMP. An investigation of different NHC precursors showed that the bulky 2,6-diisopropylphenyl moiety was necessary to achieve high coupling yields (75-85%). The corresponding ethyl analogue was moderately active (11%). A range of unsymmetrical NHC precursors were prepared and evaluated. The ligand precursor containing one 2,6-diisopropylphenyl and one 2,6-diethylphenyl afforded the coupling product in 47% yield, clearly suggesting a direct relationship between the steric topography created by the flanking N-substituents and catalyst activity. Under optimal conditions, a number of alkyl bromides and alkylzinc halides possessing common functional groups (amide, nitrile, ester, acetal, and alkyne) were effectively coupled (61-92%). It is noteworthy that β-substituted alkyl bromides and alkylzinc halides successfully underwent cross-coupling. Also, under these conditions alkyl chlorides were unaffected.
Selective rhenium-catalyzed oxidation of secondary alcohols with methyl sulfoxide in the presence of ethylene glycol, a convenient one-pot synthesis of ketals
Arterburn, Jeffrey B.,Perry, Marc C.
, p. 769 - 771 (2008/02/12)
Formula presented Secondary alcohols are oxidized preferentially by DMSO and the catalyst ReOCl3(PPh3)2 in the presence of ethylene glycol and refluxing toluene, producing the corresponding ketals. The reactions are rapid, and proceed in very good to excellent yields. The byproducts of the reaction, methyl sulfide and water, are easily removed. No epoxidation or other common side reactions were observed. This direct oxidative transformation of alcohols to the protected ketal derivatives should have broad synthetic applicability.
Percutaneous absorption enhancers, compositions containing same and method of use
-
, (2008/06/13)
Novel 1,3-dioxolanes (1,3-dioxyacyclopentanes) are provided along with new 1,3-dioxolanes (1,3-dioxacyclopentanes) compositions which are useful in enhancing the absorption of therapeutic agents through the skin of humans and animals. The method for enhancing skin penetration of therapeutic agents using 1,3-dioxacycloalkanes is also described. The preferred compounds are 1,3-dioxolanes (1,3-dioxacyclopentanes) and 1,3-dioxanes (1,3-dioxacyclohexanes). The preferred compounds have the formula: STR1 wherein R, R0, R1, R2, R3, R4, R5 and R6 are each independently selected from hydrogen and C1 to C18 aliphatic groups, preferably alkyl, alkenyl, and the halo, hydroxy, carboxy, carboxamide and carboalkoxy substituted forms thereof, with at least one of said R's an alkyl or alkenyl group of C4 to C18 and n=0 or 1; the total number of carbon atoms in all of said R groups being no more than 40, and preferably less than 20 and not more than 1 thereof containing 18 or more carbon atoms.
