Rhodium-catalyzed sequential allylic amination and olefin hydroacylation reactions: enantioselective synthesis of seven-membered nitrogen heterocycles.Angew Chem Int Ed Engl. 2014 Apr 01; 53(14):3688-92.AC
Dynamic kinetic asymmetric amination of branched allylic acetimidates has been applied to the synthesis of 2-alkyl-dihydrobenzoazepin-5-ones. These seven-membered-ring aza ketones are prepared in good yield with high enantiomeric excess by rhodium-catalyzed allylic substitution with 2-amino aryl aldehydes followed by intramolecular olefin hydroacylation of the resulting alkenals. This two-step procedure is amenable to varied functionality and proves useful for the enantioselective preparation of these ring systems.