Cinchona alkaloid-catalyzed asymmetric trifluoromethylation of alkynyl ketones with trimethylsilyl trifluoromethane.
The first catalytic enantioselective trifluoromethylation of alkynyl ketones 1 with (trifluoromethyl)trimethylsilane is disclosed by an operationally simple procedure, based on the combination of ammonium bromide of bis-cinchona alkaloids with Me(4)NF to afford trifluoromethyl-substituted tertiary propargyl alcohols (up to 96% ee), which are the important chiral building blocks for pharmaceuticals. Biologically attractive aryl heteroaryl trifluoromethyl carbinols were also synthesized.
Kawai
Hiroyuki
H
Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
Tachi
Kentaro
K
Tokunaga
Etsuko
E
Shiro
Motoo
M
Shibata
Norio
N
D000480:Alkynes / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry; D002384:Catalysis; D002930:Cinchona Alkaloids / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques; D007659:Ketones / Q000737:chemistry*; D000432:Methanol / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D020005:Propanols / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013237:Stereoisomerism; D014297:Trimethylsilyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry*
D000480:Alkynes; D001965:Bromides; D002930:Cinchona Alkaloids; D007659:Ketones; D020005:Propanols; D000644:Quaternary Ammonium Compounds; D014297:Trimethylsilyl Compounds; C028255:propargyl alcohol; C051470:ammonium bromide; D000432:Methanol