Pinacol reduction-cum-rearrangement. A re-examination of the reduction of aryl alkyl ketones by zinc–aluminum chloride
作者:Anya A. Grant、Myron Allukian、Albert J. Fry
DOI:10.1016/s0040-4039(02)00737-2
日期:2002.6
Reduction of alkyl phenyl ketones by zinc and aluminum chloride in acetonitrile results in pinacol condensation followed by rearrangement. The phenyl group migrates in every instance.
1,2-Dicarbonyl compounds reacted with benzene in the presence of a strong acid, trifluoromethanesulfonic acid, to give gem-diphenylated ketones in high yields. The reaction was accelerated when the acidity of the medium was increased, supporting involvement of O,O-diprotonated 1,2-dicarbonyl species (i.e., 1,2-dihydroxyethylene dications) as the active electrophiles.
A One-Pot Cross-Pinacol Coupling/Rearrangement Procedure
作者:Ulf Scheffler、Rainer Mahrwald
DOI:10.1002/hlca.201200402
日期:2012.10
A new catalytic retro‐pinacol/cross‐pinacol reaction, followed by subsequent rearrangement or deoxygenation of the intermediately formed vicinal diols, is described. This operationally simple one‐pot protocol allows isolation of geminal α,α‐diphenyl ketones or 1,1‐diphenyl alkenes with high yields and selectivities.