Oxidative Cross-Coupling of β,β-Difluoroenol Silyl Ethers with Nucleophiles: A Dipole-Inversion Method to Difluoroketones
摘要:
Oxidative cross-coupling of alpha-aryl-beta,beta-difluoroenol silyl ethers with heteroaromatics in the presence of Cu(OTf)(2) in wet acetonitrile proceeds smoothly, affording heteroaryldifluoromethyl aryl ketones in 61-88% yields. Alcohols also react as nucleophiles under the same conditions to provide alkoxydifluoromethyl aryl ketones in 73-80% yields.
Base-catalysed <sup>18</sup>F-labelling of trifluoromethyl ketones. Application to the synthesis of <sup>18</sup>F-labelled neutrophil elastase inhibitors
作者:Denise N. Meyer、Miguel A. Cortés González、Xingguo Jiang、Linus Johansson-Holm、Monireh Pourghasemi Lati、Mathias Elgland、Patrik Nordeman、Gunnar Antoni、Kálmán J. Szabó
DOI:10.1039/d1cc03624f
日期:——
A new method for the fluorine-18 labelling of trifluoromethyl ketones has been developed. This method is based on the conversion of a–COCF3 functional group to a difluoro enol silyl ether followed by halogenation and fluorine-18 labelling. The utility of this new method was demonstrated by the synthesis of fluorine-18 labelled neutrophil elastase inhibitors, which are potentially useful for detection
p-Toluenesulfonic Acid-Catalyzed Reaction of Phthalaldehydic Acids with Difluoroenoxysilanes: Access to 3-Difluoroalkyl Phthalides
作者:Jianguo Yang、Jun Ren、Saimei Liu、Yan Li、Feiyi Wang、Chao Ma、Guichun Yang
DOI:10.1055/a-1581-2408
日期:2022.1
A convenient approach for the synthesis of 3-difluoroalkyl phthalides has been developed from phthalaldehydic acids and difluoroenoxysilanes by using relatively inexpensive p-toluenesulfonic acid monohydrate (PTSA) as a catalyst. A series of 3-difluoroalkyl phthalides and cyclic difluoroalkyl ethers were obtained in up to 99% yield. The products obtained could be readily converted into difluoroalkyl
An efficient Fe(OTf)3-catalyzed nucleophilicsubstitution of cyclic or acyclic tertiary alcohols with difluoroenoxysilanes is developed, which provides a facile protocol for assembling structurally diverse α,α-gem-difluoroketones featuring a quaternary carbon center in good to excellent yields under mild conditions. Moreover, the diverse product elaborations highlight the utility of this protocol,
We report a highly stereoselective synthesis of all‐carbon or fluorinated tetrasubstituted alkenes from diazo reagents and fluorinated enolsilylethers, using C−F bond as a synthetic handle. Cationic AuI catalysis plays a key role in this reaction. Remarkable fluorine effects on the reactivity and selectivity was also observed.
A highly efficient metal-free aldol-type reaction of various acetals or ketals with fluorinated silylenolethers catalysed by less than 1 mol% HClO4 (70 wt%, aq.) is developed. This provides expedient access to a wide array of valuable fluoroalkyl ethers featuring a ketone carbonyl functionality in good to excellent yields (40 examples). Furthermore, the thus obtained adducts are readily elaborated