19305-01-2Relevant academic research and scientific papers
Highly selective trifluoroacetic ester/ketone metathesis: An efficient approach to trifluoromethyl ketones and esters
Zhou, Yuhan,Yang, Dongmei,Luo, Gen,Zhao, Yilong,Luo, Yi,Xue, Na,Qu, Jingping
, p. 4668 - 4674 (2014/06/23)
A highly selective and atom efficient 'trifluoroacetic ester/ketone metathesis' has been sincerely witnessed. Enolizable alkyl (at least two non-hydrogen atoms) aryl ketones were found to react readily with ethyl trifluoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones (TFMKs), and aromatic acid esters, which were quite different from the general Claisen condensation products, 1,3-diketones. The outcome of the reaction between ketone and ethyl trifluoroacetate is strongly related to the structures of substrates, the steric congestion caused by alkyl group is in favor of the C-C bond cleavage. DFT investigation further disclosed that the metathesis reaction was a kinetically favored pathway. Using only a slight excess of cheap trifluoromethylation reagent, simple operation and mild conditions make it a practical method for preparation of TFMKs on large scale, as well as a new choice of converting aryl alkyl ketones to aromatic acid esters.
Synthesis of trifluoromethyl ketones via tandem Claisen condensation and retro-Claisen C-C bond-cleavage reaction
Yang, Dongmei,Zhou, Yuhan,Xue, Na,Qu, Jingping
, p. 4171 - 4176 (2013/06/05)
A highly efficient, operationally simple approach to trifluoromethyl ketones has been developed that builds on the use of a tandem process involving Claisen condensation and retro-Claisen C-C bond cleavage reaction. Enolizable alkyl phenyl ketones were found to react readily with ethyl trifuoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones, which were quite different from the general Claisen condensation products, β-diketones. This procedure uses readily available starting materials and can be extended to the preparation of perfluoroalkyl ketones in excellent yield.
