A convenient preparation of 3,3,3-trifluoro-1-propynylamines and their Lewis acid catalyzed reaction with carbonyl compounds leading to (z)-alpha-(trifluoromethyl)-alpha,beta-unsaturated amides.
N,N-Dialkyl(3,3,3-trifluoro-1-propynyl)amines were readily prepared by a three-step procedure starting from commercially available 2,2,3,3,3-pentafluoropropanol. These fluorinated alkynylamines reacted smoothly with a variety of aldehydes or ketones in the presence of a catalytic amount of Lewis acid and molecular sieves 4A at ambient temperature to produce the corresponding alpha-(trifluoromethyl)-alpha,beta-unsaturated amides in good to excellent yields with high Z-stereoselectivity.
Mantani
T
T
Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
Shiomi
K
K
Konno
T
T
Ishihara
T
T
Yamanaka
H
H