16358-71-7Relevant articles and documents
Large-steric hindrance chiral quaternary ammonium salt phase transfer catalyst derived from cinchona alkaloid and synthesis method thereof
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Paragraph 0054-0058, (2021/10/27)
The invention discloses a large-steric hindrance chiral quaternary ammonium salt phase transfer catalyst derived from cinchona alkaloid. The invention belongs to the technical field of asymmetric catalysis. In the invention, the cinchona alkaloid is disso
Catalytic Asymmetric Hydroalkenylation of Vinylarenes: Electronic Effects of Substrates and Chiral N-Heterocyclic Carbene Ligands
Ho, Chun-Yu,Chan, Chun-Wa,He, Lisi
, p. 4512 - 4516 (2015/04/14)
An asymmetric tail-to-tail cross-hydroalkenylation of vinylarenes with terminal olefins was achieved by catalysis with NiH complexes bearing chiral N-heterocyclic carbenes (NHCs). The reaction provides branched gem-disubstituted olefins with high enantioselectivity (up to 94% ee) and chemoselectivity (cross/homo product ratio: up to 99:1). Electronic effects of the substituents on the vinylarenes and on the N-aryl groups of the NHC ligands, but not a π,π-stacking mechanism, assist the steric effect and influence the outcome of the cross-hydroalkenylation.
Enantioselective copper-catalyzed 1,4-addition of dialkylzincs to enones followed by trapping with allyl iodide derivatives
Kawamura, Kenjiro,Fukuzawa, Hitomi,Hayashi, Masahiko
supporting information; experimental part, p. 640 - 647 (2011/08/06)
Enantioselective copper-catalyzed 1,4-addition of dialkylzincs to enones proceeded in the presence of 0.1 mol% of Cu(OTf)2 and 0.25 mol% of an N,N,P-ligand containing a quinoline moiety to afford the corresponding conjugated adducts in 99%ee. The intermediate zinc enolates were trapped with substituted allyl iodides to give disubstituted ketones with high diastereoselectivity and enantioselectivity.