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Jung Woon Yang

Publications and source records attributed to Jung Woon Yang.

10 recordsLinked to original sources
PubMed2005

Catalytic asymmetric reductive Michael cyclization.

A highly efficient and chemo-, regio-, diastereo-, and enantioselective organocatalytic tandem conjugate reduction-Michael cyclization of enal enones has been developed. Accordingly, treating the enal enone with a Hantzsch dihydropyridine in the presence of a catalytic amount of an imidazolidinone organocatalyst provides cyclic keto aldehydes in high yields and enantiomeric excesses. The reaction works well with aliphatic and aromatic substrates in the synthesis of five- and six-membered carbacyclic derivatives.

Journal Article↗
PubMed2002

Osmium tetroxide anchored to porous resins bearing residual vinyl groups: a highly active and recyclable solid for asymmetric dihydroxylation of olefins.

[reaction: see text] OsO(4) was simply immobilized onto resins such as Amberlite XAD-4 or XAD-7 bearing residual vinyl groups. The resulting osmylated resins are air-stable, nonvolatile, and much easier to handle than their homogeneous counterpart (OsO(4)). Moreover, the resin-bound OsO(4) exhibited excellent catalytic activity in the asymmetric dihydroxylation of olefins and was easily recovered and reused in five consecutive reactions without any significant decrease in product yield. Turnover time, however, was significantly increased for the fourth and fifth reactions.

Journal Article↗