[reaction: see text] The radical trifluoromethylation of ketonesilylenolethers gave alpha-CF(3) ketones in good yields with wide scope of the ketonic substrates including acyclic ketones and cyclopentanone. The use of dialkylzinc to activate the silylenolethers is the key to the efficient radical trifluoromethylation.
Dialkylzinc-accelerated α-Trifluoromethylation of Carbonyl Compounds Catalyzed by Late-transition-metal Complexes
作者:Yuichi Tomita、Yoshimitsu Itoh、Koichi Mikami
DOI:10.1246/cl.2008.1080
日期:2008.10.5
Trifluoromethylation of ketone silyl enol ethers is found to be significantly accelerated by late-transition-metal catalysts and dialkylzincs to give α-trifluoromethyl ketones in good yields. Addition of dialkylzinc is the key to the high yielding α-trifluoromethylation of carbonyl compounds.
Ketone zincate-type enolates can be applied to radical trifluoromethylation for the general synthesis of alpha-CF3-ketones, cyclopentanones in particular. The addition of diethylzinc to lithium enolates is the key in the preparation of the zincate-type enolates for efficient radical trifluoromethylation. (c) 2007 Elsevier Ltd. All rights reserved.