Copper-Catalyzed Fluoroolefination of Silyl Enol Ethers and Ketones toward the Synthesis of β-Fluoroenones
作者:Yanlin Li、Jing Liu、Shuang Zhao、Xuzhao Du、Minjie Guo、Wentao Zhao、Xiangyang Tang、Guangwei Wang
DOI:10.1021/acs.orglett.7b03700
日期:2018.2.16
A general and facile synthetic method for β-fluoroenones from silylenolethers or ketones, with a copper–amine catalyst system, has been developed. The reaction proceeded by a tandem process of difluoroalkylation–hydrolysis–dehydrofluorination. This method is characterized by high yields, excellent Z/E ratios, a low-cost catalyst, and a broad substrate scope. The synthetic potential of β-fluoroenones
Photocatalytic Vicinal Aminopyridylation of Methyl Ketones by a Double Umpolung Strategy
作者:Honggu Im、Wonjun Choi、Sungwoo Hong
DOI:10.1002/anie.202008435
日期:2020.9.28
umpolung strategy for the vicinal aminopyridylation of ketones was developed using pyridinium N−N ylides. The inversion of the polarity of the pyridinium N−N ylides by single‐electron oxidation successfully enables radical‐mediated 1,3‐dipolar cycloadditions with enolsilanes formed in situ from ketones, followed by homolytic cleavage of the N−N bond. Intriguingly, the nucleophilic amino and electrophilic
Reported herein is a visible‐light‐mediated radical approach to the α‐alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2‐based activation of alkyl halides and blue light irradiation. The resulting open‐shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl
Ring-Closing Metathesis Reactions on Azinium Salts: Straightforward Access to Quinolizinium Cations and Their Dihydro Derivatives
作者:Ana Nuñez、Beatriz Abarca、Ana M. Cuadro、Julio Alvarez-Builla、Juan J. Vaquero
DOI:10.1021/jo900292b
日期:2009.6.5
proved to be an efficient approach to 3,4-dihydro- and 1,2-dihydroquinolizinium salts and the corresponding quinolizinium derivatives by an improved thermal oxidation in the presence of Pd/C without solvent. A comparative study showed that the quinolizinium system was obtained in better yields through the 3,4-dihydroquinolizinium route, thus allowing the synthesis of quinolizinium derivatives or improvements