Chiral 2,2′-Binaphthyldiimine–Nickel(II) Complexes as Lewis Acid Catalysts for Enantioselective Diels–Alder Reactions
作者:Hiroyuki Suga、Akikazu Kakehi、Masashi Mitsuda
DOI:10.1246/bcsj.77.561
日期:2004.3
The preparation and application of a novel class of chiral Lewisacid catalysts based on chiral 2,2′-binaphthyldiimine ligands are described. Among the binaphthyldiimine–metal complexes tested, N,N...
A process for performing a catalytic Diels-Alder reaction by reacting a diene with a dienophile in the presence of a heterogeneous catalyst comprising a zeolitic material exchanged or impregnated with ions of a Lewis acidic metal is described. The catalyst, for example, copper-exchanged zeolite Y, may be treated with chiral bis(imine) compounds to direct the chirality of the reaction products. The catalyst can be separated from the reaction mixture and re-used in further Diels Alder reactions.
zine ligands 2 were applied in asymmetric catalysis. Rhodium and copper complexes catalyzed the hydrosilylation of acetophenone and [4+2] cycloadditions with moderate enantioselectivity. Iridium complexes were used to hyrogenate di-, tri-, and tetrasubstituted alkenes, giving products with moderate to high enantiomer excesses. Enantioselective allylic substitution and Heckreactionscatalyzed by [
The Preparation and Utility of Bis(sulfinyl)imidoamidine Ligands for the Copper-Catalyzed Diels−Alder Reaction
作者:Timothy D. Owens、Andrew J. Souers、Jonathan A. Ellman
DOI:10.1021/jo020524c
日期:2003.1.1
The design and preparation of a novel class of ligands based on the sulfinyl imine functionality is described. In particular, an efficient and modular synthesis of bis(sulfinyl)imidoamidine (siam) ligands is reported. The versatility of the synthetic sequence is demonstrated by the preparation of various analogues to explore the effect of substitution about the ligand framework on catalytic activity
Chiral cationic palladium[bond]phosphinooxathiane complexes have been found to be effective catalysts for enantioselective Diels-Alder (DA) reaction of cyclopentadiene with acyl-1,3-oxazolidin-2-ones to give the corresponding DA adducts in good yield and high enantioselectivity up to 93% ee.