Byung Tae Cho

Highly efficient synthesis of chiral β-hydroxy sulfides with high enantiomeric purity via CBS-oxazaborolidine-catalyzed borane reduction

Abstract A simple and efficient synthesis of chiral β-hydroxy p -tolylsulfides with high enantiomeric purity by CBS-oxazaborolidine-catalyzed asymmetric borane reduction of β-keto p -tolylsulfides using N -ethyl- N -isopropylaniline–borane complex as the borane carrier is reported.

Application of optically active 1,2-diol monotosylates for synthesis of β-azido and β-amino alcohols with very high enantiomeric purity. Synthesis of enantiopure (R)-octopamine, (R)-tembamide and (R)-aegeline

A very convenient and highly efficient synthesis of near enantiopure β-azido and β-amino alcohols including biologically active substances such as (R)-octopamine, (R)-tembamide and (R)-aegeline from optically active 1,2-diol monotosylates is reported.

Enantioselective addition of diethylzinc to aldehydes catalyzed by a new chiral β-amino alcohol derived from d-mannitol

Abstract A new chiral β-dialkylamino alcohol 1 prepared from d -mannitol has been used as a highly effective chiral catalyst for the enantioselective addition of diethylzinc to unhindered aliphatic aldehydes to afford the product alcohols in up to 94% ee.

Efficient synthesis of optically active β-hydroxy p-tolylsulfones with very high enantiomeric excess via CBS–oxazaborolidine-catalyzed borane reduction

Abstract A simple, efficient synthesis of optically active β-hydroxy p -tolylsulfones with >99% e.e. by employing CBS–oxazaborolidine-catalyzed asymmetric borane reduction of β-keto p -tolylsulfones using N -ethyl- N - iso -propylaniline–borane complex as the borane carrier has been established.

A practical method for synthesis of terminal 1,2-diols in high enantiomeric excess via oxazaborolidine-catalyzed asymmetric reduction

Abstract Asymmetric borane reduction of α-hydroxy ketones protected with a tetrahydropyranyl (THP) group catalyzed by Coreys CBS reagent using N -phenylamine–borane complexes as the hydride source provided the corresponding terminal 1,2-diols with a very high enantiomeric excess.

Enantioselective addition of diethylzinc to aldehydes using γ-aminoalcohols derived from α-D-xylose as new chiral catalysts

Abstract The enantioselective addition of diethylzinc to aldehydes using 1,2-isopropylidene-5-deoxy-5-dialkylamino-α-D-xylofuranoses derived from α-D-xylose as new catalysts provided the corresponding alcohols with 75–96 % ee.

Asymmetric reduction of N-substituted ketimines with the reagent prepared from borane and (S)-(–)-2-amino-3-methyl-1,1-diphenylbutan-1-ol (itsuno's reagent): enantioselective synthesis of optically active secondary amines

Itsunos Reagent (1) reduced N-substituted ketimines in very high yields to the corresponding amines with high optical induction.

Enantioselective synthesis of optically active β-aminoalcohols via asymmetric reduction

Abstract Optically active β-aminoalcohol derivatives were prepared by asymmteric reduction of the coiresponding aminoketones with a chiral borohydride, K glucoride ( 1 ).

Facile synthesis of chiral isopropyl carbinols with high enantiomeric excess via catalytic enantioselective addition of diisopropylzinc to aldehydes

Abstract Highly effective syntheses of chiral alkyl and aryl isopropyl carbinols with high enantiomeric excess (94–98% ee) via catalytic enantioselective addition of diisopropylzinc to aldehydes have been developed.

Enantioselective synthesis of optically active metolachlor via asymmetric reduction

Abstract Optically active metolachlor was prepared by chloroacetylation of the corresponding amine obtained by asymmetric reduction of the requisite imine with the chiral hydrides, such as Itsunos reagent ( 4 ), Coreys reagent ( 5 ) and K glucoride ( 6 ).