Beilstein J. Org. Chem.2012,8, 658–661, doi:10.3762/bjoc.8.73
, Japan 10.3762/bjoc.8.73 Abstract A triflicimide (Tf2NH) catalyzed isomerization of kinetically favourable silyl enol ethers into thermodynamically stable ones was developed. We also demonstrated a one-pot catalytic reaction consisting of (2 + 2) cycloaddition and isomerization. In the reaction
sequence, Tf2NH catalyzes both of the reactions.
Keywords: isomerization; one-pot reaction; organocatalysis; silyl enol ethers; triflicimide; Introduction
Silyl enol ethers, which are isolable equivalents of metal enolates, are useful and important intermediates in synthetic chemistry [1][2][3]. They
on triflicimide (Tf2NH)-catalyzed reactions [8], we accidentally found that the isomerization of kinetically favourable silyl enol ethers into thermodynamically stable ones occurs smoothly in the presence of Tf2NH. When the TBS enol ether 1a was treated with a catalytic amount of Tf2NH (1.0 mol
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Graphical Abstract
Scheme 1:
Plausible mechanism for Tf2NH-catalyzed isomerization of silyl enol ethers.