An effective asymmetric α-phenylation of methylketones with triphenylaluminium in the presence of (+)-benzopyranoisoxazolidine has been developed. The reaction proceeds via the in situ formation of a chiral N-alkoxyenamine and the subsequent diastereoselective nucleophilic phenylation to provide α-phenylated products in moderate to good yields, with high enantioselectivities.
The present disclosure relates to compounds, compositions and methods for the treatment of hepatitis C virus (HCV) infection. Also disclosed are pharmaceutical compositions containing such compounds and methods for using these compounds in the treatment of HCV infection.
作者:Eugenio Gandolfo、Xinjun Tang、Sudipta Raha Roy、Paolo Melchiorre
DOI:10.1002/anie.201910168
日期:2019.11.18
Photochemical enantioselective nickel-catalyzed cross-coupling reactions are difficult to implement. We report a visible-light-mediated strategy that successfully couples symmetrical anhydrides and 4-alkyl dihydropyridines (DHPs) to afford enantioenriched α-substituted ketones under mild conditions. The chemistry does not require exogenous photocatalysts. It is triggered by the direct excitation of
A stereoselectivehypervalent iodine-promoted oxidative rearrangement of 1,1-disubstituted alkenes has been developed. This practically simple protocol provides access to enantioenriched α-arylated ketones without the use of transition metals from readily accessible alkenes.
BVMO-catalysed dynamic kinetic resolution of racemic benzyl ketones in the presence of anion exchange resins
作者:Cristina Rodríguez、Gonzalo de Gonzalo、Ana Rioz-Martínez、Daniel E. Torres Pazmiño、Marco W. Fraaije、Vicente Gotor
DOI:10.1039/b922693a
日期:——
fluorescens ACB was employed in the presence of a weak anion exchange resin to perform dynamic kinetic resolutions of racemic benzyl ketones with high conversions and good optical purities. Different parameters that affect to the efficiency of the enzymatic Baeyer–Villiger oxidation and racemisation were analyzed in order to optimize the activity and selectivity of the biocatalytic system.