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.
Iron(II) complexes are suitable catalysts for the isomerization of trifluoromethylated allylic alcohols. Synthesis of trifluoromethylated dihydrochalcones
We demonstrated that iron(II) complexes can substitute platinum metals as well as iron(0) carbonyls for the isomerization of γ-trifluoromethylated allylic alcohols into β-trifluoromethylated ketones. In particular, iron(II)-tetra(isonitrile) complexes were employed for the synthesis of a series of trifluoromethylated dihydrochalcones variously decorated on each aromatic ring.
β-Trifluoromethylated ketones were synthesized from the corresponding α-trifluoromethylated styrenes and aromatic carboxylic acids by photoredox catalysis. This method involves phosphoranyl radical promoted deoxygenation of aromatic acids and hydroacylation of α−CF3 styrenes with the generated acyl radicals.