Spray-dried potassiumfluoride was found to be much less hygroscopic and much more effective as a fluorinating agent than usual calcine-dried potassiumfluoride. Organic compounds containing an activated halogen atom were readily fluorinated in acetonitrile with spray-dried potassiumfluoride.
Transition metal-free hydrodefluorination of acid fluorides and organofluorines by Ph<sub>3</sub>GeH promoted by catalytic [Ph<sub>3</sub>C][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>]
fluorides directly to their corresponding aldehydes without over-reduction via the conversion of Ph3GeH to the germylium cation [Ph3Ge]+ by a catalytic amount of the tritylium salt [Ph3C][B(C6F5)4]. Here, no transition metalcatalyst is required and there is no decarbonylation of the acid fluoride, which are advantages over existing methods. The fluorine atoms can also be abstracted from organofluorine
Versatile Palladium-Catalyzed Approach to Acyl Fluorides and Carbonylations by Combining Visible Light- and Ligand-Driven Operations
作者:Yi Liu、Cuihan Zhou、Meijing Jiang、Bruce A. Arndtsen
DOI:10.1021/jacs.2c01951
日期:2022.6.1
We describe the development of a general palladium-catalyzed carbonylative method to synthesize acyl fluorides from aryl, heteroaryl, alkyl, and functionalized organic halides. Mechanistic analysis suggests that the reaction proceeds via the synergistic combination of visible light photoexcitation of Pd(0) to induce oxidative addition with a ligand-favored reductive elimination. These together create
A Single‐Atom Cobalt Catalyst for the Fluorination of Acyl Chlorides at Parts‐per‐Million Catalyst Loading
作者:Wen‐Hao Li、Bo‐Chao Ye、Jiarui Yang、Ye Wang、Chang‐Jie Yang、Ying‐Ming Pan、Hai‐Tao Tang、Dingsheng Wang、Yadong Li
DOI:10.1002/anie.202209749
日期:2022.10.4
A Co single-atom catalyst was synthesized via thermal decomposition of a zeolitic imidazolate framework (ZIF). The Co1−N4@NC catalyst generated a stable Co−F intermediate in situ through an oxidative fluorination pathway to replace the substitution fluorination of the unstable high-valent Co system. In the presence of Co−F intermediates, KF can be used to replace AgF. Co1−N4@NC exhibited ultrahigh
Oxidation of primary aliphatic aldehydes with p-trifluoromethylphenyl(difluoro)-lambda(3)-bromane in dichloromethane at 0 degrees C afforded acid fluorides selectively In good yields, while that of aromatic aldehydes In chloroform at room temperature produced aryl difluoromethyl ethers. A larger migratory aptitude of aryl groups compared to primary alkyl groups during a 1,2-shift from carbon to an electron-deficient oxygen atom in bromane(III) Criegee-type intermediates will result in these differences in the reaction courses.