Le catalyseur chiral est genere a partir de TiCl 2 (i-PrO) 2 et du (methyl-2 phenyl-2, α,α,α',α'-tetraphenyl) dioxolanne-1,3 dimethanol-4,5,chiral
Le catalyseur chiral estgenere a partir de TiCl 2 (i-PrO) 2 et du (methyl-2 phenyl-2, α,α,α',α'-tetraphenyl) dioxolanne-1,3 dimethylethanol-4,5,chiral
Asymmetric Diels-Alder reactions catalyzed by chiral lanthanide(III) trifluoromethanesulfonates. Unique structure of the triflate and stereoselective synthesis of both enantiomers using a single chiral source and a choice of achiral ligands
were stereoselectively prepared by using a single chiral source, R-(+)-binaphthol, and a choice of achiral ligands. When 3-acetyl-1,3-oxazolidin-2-one was combined with the original catalyst system consisting of lanthanide triflate, R-(+)-binaphthol, and cis-1,2,6-trimethylpiperidine, a new catalyst was generated (catalyst A). In the presence of this catalyst, 3-acyl-1,3-oxazolidin-2-ones reacted with
ASYMMETRIC DIELS–ALDER REACTION PROMOTED BY A CHIRAL TITANIUM REAGENT
作者:Koichi Narasaka、Masayuki Inoue、Naoko Okada
DOI:10.1246/cl.1986.1109
日期:1986.7.5
The asymmetricDiels–Alderreaction between prochiral dienes and dienophiles prepared from α,β-unsaturated acids and 1,3-oxazolidin-2-one proceeds by the use of a chiral alkoxy titanium(IV) to give the corresponding cycloadducts in high enantioselectivity.
The Asymmetric Diels–Alder Reaction by the Use of a Catalytic Amount of a Chiral Titanium Reagent
作者:Koichi Narasaka、Masayuki Inoue、Tohru Yamada
DOI:10.1246/cl.1986.1967
日期:1986.11.5
The Diels–Alder reaction between prochiral dienophiles and cyclopentadiene proceeds in an enantioselective manner by the use of a catalytic amount of a chiral alkoxy titanium(IV) in the presence of Molecular Sieves 4A.
Lanthanide(III)-Catalyzed Enantioselective Diels-Alder Reactions. Stereoselective Synthesis of Both Enantiomers by Using a Single Chiral Source and a Choice of Achiral Ligands
作者:Shu Kobayashi、Haruro Ishitani
DOI:10.1021/ja00088a056
日期:1994.5
approach to obtaining bothenantiomers; choice of enatiofacial selectivity by use of the enatiomerically same chiralsource and different achiralligands. Bothenantiomers of the Diels-Alder adducts between e-acyl-1,3-oxazolidin-2-ones and cyclopentadiene were prepared by chirallanthanides(III)-catalyzedreactionsusing the same chiralsource, (R)-(+)-binaphthol. It is noted that the chiral catalysts with