51765-79-8Relevant articles and documents
A Photochemical Organocatalytic Strategy for the α-Alkylation of Ketones by using Radicals
Goti, Giulio,Melchiorre, Paolo,O?eka, Maksim,Schweitzer-Chaput, Bertrand,Spinnato, Davide
, p. 9485 - 9490 (2020)
Reported herein is a visible-light-mediated radical approach to the α-alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2-based activation of alkyl halides and blue light irradiation. The resulting open-shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl halides through a traditional two-electron path. The mild reaction conditions allowed functionalization of the α position of ketones with functional groups that are not compatible with classical anionic strategies. In addition, the redox-neutral nature of this process makes it compatible with a cinchona-based primary amine catalyst, which was used to develop a rare example of enantioselective organocatalytic radical α-alkylation of ketones.
PREPARATION AND REACTIONS OF SOME 2-THIENYL AND 3-THIENYL PYRIDAZINONES AND PYRIDAZINES
Powell, Paul,Sosabowski, Michael H.
, p. 1840 - 1852 (2007/10/03)
The preparation and reactions of some pyridazinone derivatives with 2- and 3-thienyl substituents are described.Precursor 4-oxobutanoic acids Ar2COCH2CH(Ar1)CO2H (Ar1=Pb, Ar2=2-thienyl and Ar1=2-thienyl, Ar2=Pb) were obtained by addition of HCN to the chalcones Ar1CH=CHCOAr2 followed by acid hydrolysis of the resulting nitrile.Nitriles, ArCOCH(CH3)CH2CN were prepared by the Michael-Stetter reaction and converted via the acids to the 4,5-dihydropyridazin-3(2H)-ones.Two methods wereused to obtain pyridazin-3(2H)-ones viz oxidation of the 4,5-dihydro derivatives with selenium dioxide and base-catalyzed condensation of methanal or aryl aldehydes at the 4-position of the 4,5-dihydro compound.
