ABSTRACT
A versatile Co(III)-catalyzed C6-selective C-H activation/pyridine migration of 2-pyridones with available propiolates as coupling partners was demonstrated. This method features high atom economy, excellent regioselectivity, and good functional group tolerance by employing an inexpensive Co(III) catalyst under mild reaction conditions. Moreover, gram-scale synthesis and late-stage modifications of pharmaceuticals were performed to prove the effectiveness of these synthetic approaches.
ABSTRACT
A palladium-catalyzed olefination of meta-C-H bonds in arenes containing oxyamides using a nitrile template as the directing group has been established. The methodology exhibited high meta-selectivity and tolerated different functional groups such as benzyloxyamides and olefin substrates. The desired products were obtained in good yields. This approach enabled the modification of natural products and drugs and was also applicable on the gram-scale. Furthermore, the directing template was readily removed by selective cleavage of the amide bond or the O-N bond to obtain meta-functionalized hydroxylamines and benzyl alcohols. The proposed method holds great potential for the design of novel drugs.
Subject(s)
Alkenes , Palladium , Palladium/chemistry , Catalysis , Alkenes/chemistry , Amides , Benzyl AlcoholsABSTRACT
An atroposelective Friedländer heteroannulation reaction of 2-aminoaryl ketones with α-methylene carbonyl derivatives has been developed for the first time with chiral phosphoric acid as an efficient organocatalyst. The desired enantioenriched axially chiral polysubstituted 4-arylquinoline architectures were prepared with good to high yields and enantioselectivities (up to 94% yield and up to 97% ee). Furthermore, the products can be readily derivatized to afford an array of new quinoline-containing heteroatropisomers, which hold great potential in asymmetric catalysis and drug discovery.
Subject(s)
Ketones/chemistry , Phosphoric Acids/chemistry , Quinolines/chemical synthesis , Catalysis , Molecular Structure , Quinolines/chemistry , StereoisomerismABSTRACT
A range of 3H-indoles and 2H-benzo[b][1,4]thiazines smoothly undergo asymmetric Strecker reaction with ethyl cyanoformate in the presence of a Cinchona alkaloid-based thiourea catalyst at 10 °C to give structurally diverse nitrogen-containing heterocycles in good to excellent yields and with excellent ee.