We report the enantiodivergent reaction of ketimines derived from α‐ketoesters with malononitriles using a single chiral source. The reactions using an 8‐quinolinesulfonyl cinchona alkaloid catalyst in the presence and absence of Et2Zn gave both enantiomers in high yields with high enantioselectivities (53∼99% yield, 99:1∼3:97 er). The obtained malononitrile ‐derived α‐amino acids were converted into various optically active compounds. A reaction mechanism is proposed to explain the observed enantiodivergency.
The first enantioselective reaction of α-isocyanoacetonitriles
was developed. The reaction of various α-isocyanoacetonitriles
with ketimines using cinchona alkaloid amide–Cu(II) catalysts
afforded imidazolines with consecutive tetrasubstituted stereogenic
carbon centers in good yields and high diastereo- and enantioselectivities.
The stereoselectivity of the reaction is explained on the basis of
the control experiment and density functional theory (DFT) calculations.
The products were subsequently converted into chiral compounds. This
process highlights the possible use of α-isocyanoacetonitriles
for asymmetric and organic syntheses.
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