Efficient Method for the Preparation of Carboxylic Acid Alkyl Esters or Alkyl Phenyl Ethers by a New-Type of Oxidation–Reduction Condensation Using 2,6-Dimethyl-1,4-benzoquinone and Alkoxydiphenylphosphines
A new-type of oxidation–reduction condensation proceeded smoothly to afford carboxylic acid alkyl esters or alkyl phenyl ethers in good to high yields by combined use of alkoxydiphenylphosphines (1...
Beyond the Tebbe Olefination: Direct Transformation of Esters into Ketones or Alkenes
作者:Anna M. Domżalska-Pieczykolan、Bartłomiej Furman
DOI:10.1055/s-0039-1691594
日期:2020.4
A direct, effective, and operationally simple transformation of esters into ketones or alkenes by the exclusive action of Tebbe’s reagent has been developed. The transformation utilizes the dual character of Tebbe’s reagent as both a methylenation agent and a rearrangement catalyst in the reaction of a wide range of substituted vinyl ethers. The resulting transformation involves sequential methylenation
The synthesis of hydroxyesters from carboxylic acids and unprotected amino alcohols in both continuous flow and batch processes is reported. The formation of a transient diazonium species with a dinitrite reagent is key in this transformation. The reaction conditions are compatible with a variety of functional groups.
Electrostatic catalysis by ionic aggregates: scope and limitations of Mg(ClO4)2 as acylation catalyst
作者:Asit K Chakraborti、Lalima Sharma、Rajesh Gulhane、Shivani
DOI:10.1016/j.tet.2003.08.007
日期:2003.9
Alkali and alkaline earthmetal perchlorates exhibit electrostatic catalysis in the activation of anhydrides for the acylation reaction. Perchlorates with higher values of the charge-size function of the metal ion exhibit better catalytic activity following the order Mg(ClO4)2>Ba(ClO4)2>LiClO4. Acylation of structurally diverse phenols, thiols, alcohols, and amines have been carried out with stoichiometric
Magnesium Bistrifluoromethanesulfonimide as a New and Efficient Acylation Catalyst
作者:Asit K. Chakraborti、Shivani
DOI:10.1021/jo0605142
日期:2006.7.1
room temperature and in short times. Electron-deficient and sterically hindered phenols provided excellent yields. The catalyst was found to be general for acylation with other anhydrides, such as propionic, isobutyric, pivalic, chloroacetic, and benzoic anhydrides. The rate of acylation was influenced by the electronic and steric factors associated with the anhydride. The reaction with less electrophilic