Mechanistic studies on alpha-trifluoromethylation of ketones via silyl enol ethers and its application to other carbonyl compounds.
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.
Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan.
Kazuyuki
K
Sato
Takashi
T
Yuki
Ryoji
R
Yamaguchi
Tetsuya
T
Hamano
Atsushi
A
Tarui
Masaaki
M
Omote
Itsumaro
I
Kumadaki
Akira
A
Ando
D000447:Aldehydes / Q000737:chemistry*; D005617:Chlorofluorocarbons, Methane / Q000737:chemistry*; D004952:Esters / Q000737:chemistry; D004987:Ethers / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*
D000447:Aldehydes; D005617:Chlorofluorocarbons, Methane; D004952:Esters; D004987:Ethers; D007659:Ketones; C009554:fluoroform