A Brønsted Acid Catalyst for the Enantioselective Protonation Reaction
作者:Cheol Hong Cheon、Hisashi Yamamoto
DOI:10.1021/ja8041542
日期:2008.7.1
A highly reactive and robust chiral Brønstedacidcatalyst, chiral N-triflyl thiophosphoramide, was developed. The first metal-free Brønstedacid catalyzed enantioselective protonation reaction of silyl enol ethers was demonstrated using this chiral Brønstedacidcatalyst. The catalyst loading could be reduced to 0.05 mol % without any deleterious effect on the enantioselectivity.
Development of a new Lewis base-tolerant chiral LBA and its application to catalytic asymmetric protonation reaction
作者:Cheol Hong Cheon、Tatsushi Imahori、Hisashi Yamamoto
DOI:10.1039/c0cc02492a
日期:——
A new Lewis base-tolerant LBA (LewisAcidAssistedBronstedAcid) derived from La(OTf)(3) and (S)-HOP has been developed as a new chiralBronstedacid. This acid has been successfully applied as a catalyst to asymmetric protonation reactions of silylenolethers of 2-substituted cyclic ketones.
[EN] PALLADIUM-CATALYZED ASYMMETRIC (HETERO)ARYLATION AND VINYLATION OF KETONE ENOLATES TO PRODUCE TERTIARY STEREOCENTERS AT ALPHA(α)-POSITION<br/>[FR] (HÉTÉRO)ARYLATION ET VINYLATION ASYMÉTRIQUES D'ÉNOLATES DE CÉTONES CATALYSÉES AU PALLADIUM PERMETTANT DE PRODUIRE DES STÉRÉOCENTRES TERTIAIRES EN POSITION ALPHA(&Agr;)
申请人:NANAYNG TECHNOLOGICAL UNIVERSITY
公开号:WO2014109712A1
公开(公告)日:2014-07-17
The invention relates to new ligands that are used in a palladium source catalyst system and in palladium catalyzed method for asymmetric α-(hetero)arylation and a-vinylation of ketones. The invention further relates to a process for preparing an asymmetric α-(hetero)arylated or a-vinylated ketone which comprises reacting the tin enolate of the ketone in the presence of catalyst system comprising a ligand of the invention and palladium source. By means of the ligands and process of the invention a stereogenic center in position a of the ketone is established with high enantiomeric excess.