Novel access to N,N′-diaryl-trans-1,2-diaminocyclohexane ligands. A cheap and easy way to prepare ligand for asymmetric transfer hydrogenation

Aerobic Dehydrogenative Aromatization in the Preparation of 4-Aminoquinoline Derivatives by Synergistic Pd/Cu Catalysis

The 4-aminoquinoline moiety is widely present in various bioactive compounds and marketed drugs, while the preparation of this target structure relies heavily on the amination of 4-chloroquinolines. Herein, an atom and step economic procedure was developed based on an aerobic dehydrogenative aromatization strategy. Unlike the well-known palladium-catalyzed dehydrogenative aromatization of cyclohexanones with amines, synergistic Pd/Cu catalysis is crucial for 2,3-dihydroquinolin-4(1H)-one type of substrates. Under the optimized conditions, a range of aromatic/aliphatic amines and 2,3-dihydroquinolin-4(1H)-ones were coupled to give the corresponding 4-aminoquinoline products in moderate to high yields, and the application of the current methodology for the preparation and late-stage diversification of marketed drugs was also demonstrated.

Asymmetric hydrogenation of trifluoromethyl ketones: application in the synthesis of Odanacatib and LX-1031

The asymmetric hydrogenation of trifluoromethyl ketones via iridium catalysis to access chiral secondary 2,2,2-trifluoroethanols is presented. The key intermediates of Odanacatib and LX1301 were prepared with high yields and enantioselectivities.

Asymmetric Hydrogenation of Aryl Perfluoroalkyl Ketones Catalyzed by Rhodium(III) Monohydride Complexes Bearing Josiphos Ligands

The asymmetric hydrogenation of 2,2,2-trifluoroacetophenones and aryl perfluoroalkyl ketones was developed using a unique, well-defined chloride-bridged dinuclear rhodium(III) complex bearing Josiphos-type diphosphine ligands. These complexes were prepared from [RhCl(cod)]₂ , Josiphos ligands, and hydrochloric acid. As catalyst precursors, they allow for the efficient and enantioselective synthesis (up to 99 % ee) of chiral secondary alcohols with perfluoroalkyl groups. This system does not require an activating base for the hydrogenation of 2,2,2-trifluoroacetophenones. Additionally, the enantioselective C=O hydrogenations of 2-phenyl-3-(haloacetyl)-indoles, a class of privileged structures in medicinal chemistry, is reported for the first time.