Enantioselective Cu-catalyzed 1,4-addition of Me3Al to a 4,4-disubstituted cyclohexa-2,5-dienone: Novel effect of trialkylsilylOTf on enantioselectivity
The asymmetric Cu-catalyzed conjugate addition of Me3Al to cyclohexa-2,5-dienone in the presence of 20 mol% of chiral 2-aryloxazolines and 120 mol% of TBDMSOTf gave the corresponding addition product in good yield with enantiomeric purities of up to 68% ee under mild conditions. Without TBDMSOTf, the ee was dramatically decreased, even in the presence of chiral 2-aryloxazolines. Copy
Selective Reduction of Cyclohexadienones with Fe2(CO)9 and Water
Selective monohydrogenation of cross conjugated 2,5-cyclohexadien-1-ones 1 with Fe2(CO)9 and water forming under unusually mild conditions the cyclohexadienol complexes 2 is applied to various related compounds.The regioselectivity of this reaction is tested with differently substituted derivatives.A mechanism explaining the observed regioselectivities and the pH dependence of the stereochemistry is discussed.
Eilbracht, Peter,Jelitte, Ruediger
p. 1983 - 1995
(2007/10/02)
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