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.
Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
Hiroyuki
H
Kawai
Kentaro
K
Tachi
Etsuko
E
Tokunaga
Motoo
M
Shiro
Norio
N
Shibata
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