Highly regio- and stereo-controlled Pd(0)-catalyzed nucleophilic substitution reaction for the synthesis of optically active γ-fluoroalkylated allylic alcohols
作者:Tsutomu Konno、Takashi Ishihara、Hiroki Yamanaka
DOI:10.1016/s0040-4039(00)01485-4
日期:2000.10
Pd(0)-catalyzed nucleophilicsubstitution reaction of opticallyactive α-(fluoroalkyl)allyl mesylates with various types of carboxylates proceeded regioselectively to afford the corresponding chiral γ-fluoroalkylated allylic alcohol derivatives in excellent yields without any loss of optical purities.
with various carboxylates and amines in the presence of tetrakis(triphenylphosphine)palladium(0) catalyst to give the corresponding gamma-fluoroalkylated (E)-allylic alcoholderivatives and amines, respectively, in excellent yields. In almost all cases, no other regio- and stereoisomers were produced. Application of this palladium-catalyzedallylic substitution reaction to various nonracemic mesylates
A number of stereoisomers of optically pure allylic alcohols with a trifluoromethyl group [CF3CH(OH)CH=CHR : R=Ph. C6H13] were prepared, utilizing the enantiotopic specificity of asymmetric hydrolysis of their acetates by hydrolases. Their absolute configurations were determined.
The invention lies particularly in novel compounds represented by the general formula;
in which Z means CF₃ CHF₂ CH₂F, CClF₂ CCl₂F, CHClF, CCl₃ C₂F₂ or a perfluoroalkyl group of 3 or more carbon atoms, m and n are same or different with each other and represent an integral of 1 - 20, which are ferroelectric and chiral smectic liquid crystals of a large spontaneous polarization, a high speed of response and a good orientation, and showing a liquid crystal phase of tristable state and an electoclinic effect to be used as an liquid crystal element superior in an image display response.
Synthesis of and Analysis of Thiol Additions to .beta.-Alkyl-.alpha.,.beta.-unsaturated Trifluoromethyl Ketones
作者:Russell J. Linderman、Eric A. Jamois、Scott D. Tennyson
DOI:10.1021/jo00084a009
日期:1994.3
A series of beta-alkyl-alpha,beta-unsaturated trifluoromethyl ketones have been prepared from the corresponding alpha-acetylenic trifluoromethyl ketones. The addition of sulfur nucleophiles was shown by chemical and F-19 NMR studies to proceed exclusively by 1,4-addition with no indication of any 1,2-addition products. The unsaturated trifluoromethyl ketones have been shown to be effective inhibitors of rat cytosolic glutathione-S-transferase.