Ömer Reis

Catalytic Intermolecular Aldehyde−Ketone Coupling via Acyl Phosphonates

The first catalytic intermolecular aldehyde-ketone coupling via acyl phosphonate is reported. Acyl phosphonates are potent acyl anion precursors, which generate acyl anion equivalents under the influence of cyanide anion via phosphonate-phosphate rearrangement. These anions readily react with activated ketones to form acyloin type coupling in 41-95% yields.

BUTENOLIDE ANNELATION USING A MANGANESE(III) OXIDATION. A SYNTHESIS OF 4-ARYLFURAN-2(5H)-ONES

Abstract A general procedure was developed for the annelation of a butenolide to an aromatic ketone that highlighted a manganese(III) oxidation of aromatic ketones. The oxidation of aromatic ketones with manganese(III) acetate in the presence of 2-bromoacetic acid or the Mn(II) salt of this carboxylic acid provided a regioselectively convenient synthesis of 2-(2-bromoacetoxy) ketones. An Arbuzov or Wittig reaction of 2-(2-bromoacetoxy) ketones followed by cyclisation furnished 4-arylfuran-2(5H)-ones in good yield.

Manganese(III) acetate-mediated oxidative coupling of phenylhydrazines with benzene: a novel method for biaryl coupling

The reaction of phenylhydrazines with benzene in the presence of manganese(III) acetate affords biaryls in good yields. The same reaction was carried out with similar oxidants, such as CoIII, CeIV and PbIV; among these oxidants MnIII acetate shows higher efficiency and selectivity.