1126-79-0Relevant articles and documents
OPTIMIZATION OF POLYMER-SUPPORTED OLIGOETHERS AS SOLID-LIQUID PHASE TRANSFER CATALYSTS
Heffernan, J.G.,Sherrington, D.C.
, p. 1661 - 1664 (1983)
Oligoether residues with terminal 8-quinolyl donor groups have been loaded virtually quantitatively onto polystyrene resin supports and function more effectively than dibenzo-18-crown-6 as solid/liquid phase transfer catalysts in Williamson ether syntheses.
Stealth star polymers: A new high-loading scaffold for liquid-phase organic synthesis
Reed, Neal N.,Janda, Kim D.
, p. 1311 - 1313 (2000)
(formula presented) Polyethylene glycol (PEG) has proven to be a versatile soluble-polymer support for organic synthesis, though the use of PEG has been limited by its relatively low loading (0.5 mmol/g or less). We have developed a new high-loading (1 mmol/g) soluble-star polymer based on a cyclotriphosphazene core with PEG arms that exhibit superior precipitation properties compared with those of linear PEG. Additionally, the heterocyclic core does not add interfering signals to the 1H or 13C NMR.
Use of diethoxymethane as a solvent for phase transfer-catalyzed O -alkylation of phenols
Coleman, M. Todd,Leblanc, Gabriel
, p. 732 - 736 (2010)
The effectiveness of diethoxymethane (DEM) as a solvent for O-alkylation of a variety of phenols under phase transfer conditions has been examined and evaluated. The reaction between 4-methoxy phenol and benzyl chloride was selected to compare reaction rates in various solvents and the efficiency of various PTCs. This reaction was further studied to develop a commercially amenable process complete with recycle streams and efficient product isolation. DEM is a good solvent for these types of phase transfer-catalyzed reactions and can be considered as an alternative solvent for dichloromethane and toluene.
Approximate rate constants for intermolecular additions of alkyl radicals to phenylsulfonyl oxime ethers
Kim, Sunggak,Lee, Ill Young
, p. 1587 - 1590 (1998)
Approximate rate constants for intermolecular additions of alkyl radicals to phenylsulfonyl oxime ethers (2a and 2b) have been determined to be k(a) = 9.6 x 105 M-1 s-1 at 25°C for 2a and k(a) = 7.3 x 104 M-1 s-1 at 60°C for 2b, indicating that the additions are fast and highly efficient processes. The kinetic data have been confirmed by two competition experiments.
Methylation with Dimethyl Carbonate/Dimethyl Sulfide Mixtures: An Integrated Process without Addition of Acid/Base and Formation of Residual Salts
Chan, Bun,Lui, Matthew Y.,Lui, Yuen Wai
, (2022/01/08)
Dimethyl sulfide, a major byproduct of the Kraft pulping process, was used as an inexpensive and sustainable catalyst/co-reagent (methyl donor) for various methylations with dimethyl carbonate (as both reagent and solvent), which afforded excellent yields of O-methylated phenols and benzoic acids, and mono-C-methylated arylacetonitriles. Furthermore, these products could be isolated using a remarkably straightforward workup and purification procedure, realized by dimethyl sulfide‘s neutral and distillable nature and the absence of residual salts. The likely mechanisms of these methylations were elucidated using experimental and theoretical methods, which revealed that the key step involves the generation of a highly reactive trimethylsulfonium methylcarbonate intermediate. The phenol methylation process represents a rare example of a Williamson-type reaction that occurs without the addition of a Br?nsted base.
CoII Immobilized on Aminated Magnetic-Based Metal–Organic Framework: An Efficient Heterogeneous Nanostructured Catalyst for the C–O Cross-Coupling Reaction in Solvent-Free Conditions
Mohammadinezhad, Arezou,Akhlaghinia, Batool
, p. 332 - 352 (2020/01/11)
Abstract: In this paper, we report the synthesis of Fe3O4?AMCA-MIL53(Al)-NH2-CoII NPs based on the metal–organic framework structures as a magnetically separable and environmentally friendly heterogeneous nanocatalyst. The prepared nanostructured catalyst efficiently promotes the C–O cross-coupling reaction in solvent-free conditions without the need for using toxic solvents and/or expensive palladium catalyst. Graphic Abstract: [Figure not available: see fulltext.].
