Regioselective conjugate 1,4-trifluoromethylation of alpha,beta-unsaturated ketones by the use of shelf-stable electrophilic trifluoromethylating reagents, S-(trifluoromethyl)diphenylsulfonium salts and copper under mild conditions is described. A wide range of acyclic aryl-aryl-enones and aryl-alkyl-enones were converted into beta-trifluoromethylated ketones in low to moderate yields.
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.
Base-Catalyzed Stereospecific Isomerization of Electron-Deficient Allylic Alcohols and Ethers through Ion-Pairing
作者:Samuel Martinez-Erro、Amparo Sanz-Marco、Antonio Bermejo Gómez、Ana Vázquez-Romero、Mårten S. G. Ahlquist、Belén Martín-Matute
DOI:10.1021/jacs.6b08350
日期:2016.10.12
between an allylic anion and the conjugate acid of the base results in efficient transfer of chirality. Through this mechanism, stereochemical information contained in the allylic alcohols is transferred to the ketone products. The stereospecific isomerization is also applicable for the first time to allylicethers, yielding synthetically valuable enantioenriched (up to 97% ee) enol ethers.
Photocatalytic hydroacylation of trifluoromethyl alkenes
作者:Pei Fan、Chang Zhang、Yun Lan、Zhiyang Lin、Linchuan Zhang、Chuan Wang
DOI:10.1039/c9cc07285c
日期:——
Hydrofunctionalization of trifluoromethyl alkenes is highly challenging, because the nucleophilic addition is oftentimes followed by β-F elimination in this case. By the use of tetrabutylammonium decatungstate (TBADT) as a hydrogen-atom-transfer (HAT) photocatalyst for acyl C–H activation, we successfully avoid the β-F elimination in the hydroacylation of trifluoromethyl alkenes with aldehydes. This light (390
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.