Trifluoromethylation of Allylsilanes under Copper Catalysis
作者:Satoshi Mizuta、Oscar Galicia-López、Keary M. Engle、Stefan Verhoog、Katherine Wheelhouse、Gerasimos Rassias、Véronique Gouverneur
DOI:10.1002/chem.201201707
日期:2012.7.9
Branched allylic CF3 products are accessible by copper‐catalyzed trifluoromethylation of allylsilanes with the Togni reagent I. The silyl group is critical to control the outcome of this reaction because in its absence, a product of addition between the alkene and the Togni reagent is formed preferentially. The reaction is inhibited with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) and is likely to
Trifluoromethylation of aromatic alkenes by visible-light-driven photoredox catalysis: Direct conversion of alkenes to 3-trifluoromethyl-1-propenyl and 1,3-bis(trifluoromethyl)-1-propenyl derivatives
irradiation has been developed. A Ru photocatalyst, [Ru(bpy)3](PF6)2 (bpy = 2,2′-bipyridine), is useful for the present trifluoromethylation and preferable formation of 3-trifluoromethyl-1-propenyl derivatives is observed. Use of an excess amount of Umemoto's reagent readily induces double trifluoromethylation of electron-rich alkenes, resulting in 1,3-bis(trifluoromethyl)-1-propenyl skeleton.
Trifluoromethylation of Allylsilanes under Photoredox Catalysis
作者:Satoshi Mizuta、Keary M. Engle、Stefan Verhoog、Oscar Galicia-López、Miriam O’Duill、Maurice Médebielle、Katherine Wheelhouse、Gerasimos Rassias、Amber L. Thompson、Véronique Gouverneur
DOI:10.1021/ol400184t
日期:2013.3.15
A new catalytic method to access allylic secondary CF3 products is described. These reactions use the visible light excited Ru(bpy)(3)Cl-2 center dot 6H(2)O catalyst and the Togni or Umemoto reagent as the CF3 source. The photoredox catalytic manifold delivers enantioenriched allylic trifluoromethylated products not accessible under Cu(I) catalysis.