Dae Won Kim

Publications (2)2.2 Total impact

• Article: Orthopalladated complexes as phase-transfer catalysts for asymmetric alkylation of achiral Schiff base esters

  Dae Hyun Kim, Jin Kyu Im, Dae Won Kim, Hyunjoo Lee, Honggan Kim, Hoon Sik Kim, Minserk Cheong, Deb Kumar Mukherjee
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  ABSTRACT: The asymmetric C-alkylation of benzophenone Schiff base glycine esters has been achieved using a palladium(II) chiral complex as a phase-transfer catalyst. The aromatic moiety around the metal center and various physicochemical parameters were investigated to study their effect on the asymmetric alkylation reaction under phase-transfer conditions. Moderate enantioselectivity(30–40%) was achieved under room temperature conditions, which is a significant improvement compared to no enantioselectivity with a chiral palladium-salen complex reported earlier. Computer simulation studies indicate that coordination of the metal center with Z-enolate forming a square planar complex provides a favorable steric environment where the α-carbon atom of the enolate is available for enantioselective alkylation.
  Transition Metal Chemistry 04/2012; 35(8):949-957. · 1.02 Impact Factor
• Source

  Available from: ias.ac.in

  Article: Palladium catalysed asymmetric alkylation of benzophenone Schiff base glycine esters in ionic liquids

  DAE HYUN KIM, JIN KYU IM, DAE WON KIM, MINSERK CHEONG, HOON SIK KIM, DEB KUMAR MUKHERJEE
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  ABSTRACT: Asymmetric alkyl substitution of various benzophenone Schiff base substrates under biphasic conditions proceeded using optically active Palladium(II) complexes. The corresponding products were obtained in high yields but with moderate enantiomeric excess (ee). Addition of specific ionic liquids to the reaction medium enhanced reactivity and selectivity for phase transfer catalytic (PTC) glycine alkylation. It has been found that there is an anionic influence of the ionic liquids that modify the steric environment around the enolate ion. A computer-assisted molecular design of enantioselective phase-transfer catalysis with the palladium complex and the ionic liquid has been done. Graphical AbstractCombination of an asymmetric palladium catalyst and a prochiral ionic solvent promotes glycine alkylation under mild conditions. KeywordsAsymmetric alkylation–Schiff base–phase-transfer catalysis–chiral ionic liquid
  Journal of Chemical Sciences 04/2012; 123(4):467-476. · 1.18 Impact Factor