Ruthenium-Catalyzed Conjugate Hydrogenation of α,β-Enones by in situ Generated Dihydrogen from Paraformaldehyde and Water
作者:Wanfang Li、Xiao-Feng Wu
DOI:10.1002/ejoc.201403359
日期:2015.1
Notwithstanding that the highly selective hydrogenation of α,β-enones to allylic alcohols can be realized by using Noyori's Ru bifunctional system, the selective reduction of the C=C bonds in α,β-enones without touching the C=O bonds still lacks a general, simple, and efficient procedure. Ruthenium-catalyzed conjugate hydrogenation of various α,β-enones to saturatedketones with high selectivity was investigated
Aryl substituted diketones and keto-esters, useful as antiviral agents and insecticides, are prepared by reacting an arylalkyl or arylalkenyl iodide with a metal salt of the appropriate diketone or keto-ester. The intermediate iodides are prepared by condensing a methyl cyclopropyl ketone with an aromatic aldehyde to give an arylvinyl cyclopropyl ketone, reducing the latter to an arylethyl cyclopropyl carbinol or arylvinyl cyclopropyl carbinol, treating the carbinol with phosphorus tribromide and then with zinc bromide to give an arylalkyl or arylalkenyl bromide, and then replacing the bromine atom by iodine. The invention herein claimed relates to intermediate arylethyl cyclopropyl carbinols and arylvinyl cyclopropyl carbinols wherein aryl is phenyl substituted by dialkylamino.
Aryl substituted diketones and keto-esters, useful as antiviral agents and insecticides, are prepared by reacting an arylalkyl or arylalkenyl iodide with a metal salt of the appropriate diketone or keto-ester.
Aryl substituted tertiary carbinols, useful as antiviral agents and insecticides, are prepared by reacting the Grignard reagent derived from an arylalkyl or arylalkenyl iodide with a dialkyl ketone or an alkyl alkenyl ketone; or by reacting an arylalkyl or arylalkenyl ketone with an alkyl- or alkenylmagnesium halide.
pyrazole-1-carboxamides were obtained by treatment of chalcones with semicarbazidehydrochloride in dioxane containing sodium acetate/acetic acid as a buffer solution. N-acetyl derivatives of pyrazole-1-carboxamides were isolated in good yields either by treatment of the carboxamide derivatives with acetic anhydride or refluxing chalcones with semicarbazide in ethanol containing few drops of acetic acid to give