Palladium-Catalyzed Regio- and Stereoselective Formate Reduction of Fluorine-Containing Allylic Mesylates. A New Entry for the Construction of a Tertiary Carbon Attached with a Fluoroalkyl Group
regioselective palladium-catalyzed formate reduction of γ-fluoroalkylated allylic esters is described. Reduction of the allylic esters under the influence of palladium with a monodentate phosphine ligand proceeded preferentially at the γ position, the corresponding reduction products with a fluoroalkyl group at the tertiary carbon being afforded in high yields. When the chiral allylic ester was employed
A synthetic approach to chiral β‐CF3‐substituted saturated carbonyl compounds has been developed in which ruthenium complexes efficiently catalyze the redoxisomerization of CF3‐bearing allylicalcohols by an intramolecular suprafacial enantiospecific 1,3‐hydrogen transfer (see scheme). This method was used for the enantioselective synthesis of (S)‐CF3‐citronellol.
A regioselective protocol for the synthesis of substituted allylic chlorides, bromides, and fluorides has been established. Remarkably, the method can be applied to the enantioselective synthesis of challenging chiral allylic chlorides. When the allylic halides are treated with the base triazabicyclodecene as the catalyst, a [1,3]-proton shift takes place, giving the corresponding vinyl halides in
Methyl or phenyl substitution in the allylic position of malonic esters of (E)-3-phenyl-3-trifluoromethyI-2-propen-1-ol resulted in unexpected and unprecedented stereospecific formation of the corresponding cyclopropane lactone derivatives by a multistep reaction with iodine in the presence of potassium carbonate and phase transfer catalyst. (C) 2000 Elsevier Science S.A. All rights reserved.
Synthesis of β-CF3 ketones from trifluoromethylated allylic alcohols by ruthenium catalyzed isomerization
This work describes the optimization process for the synthesis of β-trifluoromethylated ketonesfrom trifluoromethylated allylicalcohols. This transformation proceeds through a ruthenium catalyzed isomerization under mild conditions with high atom economy. The effect of the CF3 group was analyzed and it provides fundamental insights into the isomerization reaction.