Efficient and convenient entry to β-hydroxy-β-trifluoromethyl-β-substituted ketones and 2,6-disubstituted 4-trifluoromethylpyridines based on the reaction of trifluoromethyl ketones with enamines or imines
The reactions of trifluoromethyl ketones with enamines or imines are described. The reaction of trifluoroacetone with enamines or imines followed by hydrolysis gave the corresponding β-hydroxy-β-trifluoromethyl-β-methyl ketones in good yields. The reaction of trifluoromethylated β-diketones with enamines in the presence of ammonium acetate gave 4-trifluoromethylated pyridines exclusively in good yields, without any detectable amount of regioisomers.
Efficient Synthesis of γ‐Keto Esters from Enamines and EDA
作者:Dan Huang、Ming Yan、Wei‐Jie Zhao、Qi Shen
DOI:10.1081/scc-200050387
日期:2005.3.1
Abstract The reaction of enamines with ethyldiazoacetate (EDA) catalyzed by dirhodium and copper complexes provided γ‐keto esters in good yields. The influences of catalyst, reaction solvent, temperature, and structure of enamines on this transformation were investigated.
A metal-, oxidant-, and fluorous solvent-free synthesis of α-indolylketones enabled by an umpolung strategy
作者:Takumi Abe、Seiya Hirao、Toshiki Yamashiro
DOI:10.1039/d0cc04795c
日期:——
Enamines undergo α-indolization with ammonium salts in the presence of Et3N to form α-indolylketones. This is the first example of transition metal-, oxidant-, and fluorous solvent-free α-indolization of ketones. Key to the success of this convenient protocol was the use of in situ generated electrophilic indole species, as well as the use of enamines as a ketone enolate equivalent.
New reaction of enamines with aryldiazoacetates catalyzed by transition metal complexes
作者:Wei-Jie Zhao、Ming Yan、Dan Huang、Shun-Jun Ji
DOI:10.1016/j.tet.2005.03.093
日期:2005.6
The reaction of aryldiazoacetates with enamines catalyzed by copper and rhodium complexes provided γ-keto esters in good yields. A full investigation of the effects of solvents, catalysts, enamines and aryldiazoacetates on the reaction was carried out. Careful analysis of the crude reaction mixture revealed a substituted enamine as the primary product, which was hydrolyzed over silica gel to give a
Reactions of Enamines with Selectfluor: A Straightforward Route to Difluorinated Carbonyl Compounds
作者:Weimin Peng、Jean'ne M. Shreeve
DOI:10.1021/jo0506837
日期:2005.7.1
Reactions of enamines, preformed from β-dicarbonyl and monocarbonyl compounds, with Selectfluor (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) under mild conditions (triethylamine (TEA) or molecular sieves) easily led to the corresponding difluorinated carbonylcompounds in high yields.