Mechanistic studies on alpha-trifluoromethylation of ketones via silyl enol ethers and its application to other carbonyl compounds
Sato, Yuki, Yamaguchi, Hamano, Tarui, Omote, Kumadaki, Ando (2009) Mechanistic studies on alpha-trifluoromethylation of ketones via silyl enol ethers and its application to other carbonyl compounds J Org Chem (IF: 3.3) 74(10) 3815-9Abstract
Synthesis of alpha-CF(3) carbonyl compounds has been recognized to be difficult up to now because the polarization of CF(3)(delta-)-I(delta+) is opposite to that of CH(3)(delta+)-I(delta-), and this makes it difficult to introduce CF(3)(+) unit to enolates. We recently reported an effective alpha-trifluoromethylation of ketones by using Et(2)Zn with Rh catalyst, but the mechanism has not fully been cleared. Now, we carried out the detailed mechanistic studies and found the involvement of a highly reactive alkylrhodium complex which derived from Et(2)Zn and RhCl(PPh(3))(3) in this alpha-trifluoromethylation. Furthermore, this alpha-trifluoromethylation was applied to other types of carbonyl compounds in good yields.
Links
http://www.ncbi.nlm.nih.gov/pubmed/19366204http://dx.doi.org/10.1021/jo9004348
