The Cinchona Primary Amine-Catalyzed Asymmetric Epoxidation and Hydroperoxidation of α,β-Unsaturated Carbonyl Compounds with Hydrogen Peroxide
作者:Olga Lifchits、Manuel Mahlau、Corinna M. Reisinger、Anna Lee、Christophe Farès、Iakov Polyak、Gopinadhanpillai Gopakumar、Walter Thiel、Benjamin List
DOI:10.1021/ja402058v
日期:2013.5.1
Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogenperoxide as the oxidant, we have developed highly enantioselective Weitz-Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonylcompounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5-15-membered cyclic enones, and
N-HETEROCYCLIC CARBENE-AMIDO PALLADIUM(II) CATALYSTS AND METHOD OF USE THEREOF
申请人:Jung Kyung Woon
公开号:US20100036131A1
公开(公告)日:2010-02-11
A new N-heterocyclic catalyst system which contains N-heterocyclic carbene and amido as ligands, which are strongly bound to a palladium metal. Another heteroatom functionality can be used as a third ligand L. The NHC-amidate ligand system is unique in structure, and shows excellent reactivities in a number of chemical reactions. The chemical reactions include carbon-carbon and carbon-heteroatom (oxygen and nitrogen) bond formations, and oxidation reactions of saturated carbon chemicals via C—H activation.
Catalytic Asymmetric Epoxidation of α-Branched Enals
作者:Olga Lifchits、Corinna M. Reisinger、Benjamin List
DOI:10.1021/ja1037935
日期:2010.8.4
An asymmetric catalytic epoxidation of alpha-branched, alpha,beta-unsaturated aldehydes is presented. A highly synergistic combination of a primary cinchona-based amine and a chiral phosphoric acid was found to promote the reaction with excellent enantiocontrol for alpha-monosubstituted and alpha,beta-disubstituted enals.
Asymmetric Intermolecular Boron Heck-Type Reactions via Oxidative Palladium(II) Catalysis with Chiral Tridentate NHC-Amidate-Alkoxide Ligands
作者:Kyung Soo Yoo、Justin O’Neill、Satoshi Sakaguchi、Richard Giles、Joo Ho Lee、Kyung Woon Jung
DOI:10.1021/jo901977n
日期:2010.1.1
Chiral dimeric tridentate NHC-amidate-alkoxide palladium(II) complexes, 3a and 3b, effected oxidative boron Heck-type reactions of aryl boronicacids with both acyclic and cyclic alkenes at room temperature to afford the corresponding coupling products with high enantioselectivities. The high degree of enantioselection, far superior to existing methods, stems from differences in the nonbonding interactions