Rhodium-Catalyzed Hydrogenation of β-Keto Enamides

Significance

The 1,3-aminoalcohol fragment can be found in a large number of synthetically and commercially important compounds; diastereoselective substrate-controlled reduction of enantiomerically pure compounds represents the most common approach to building this fragment. In this paper the authors considered the possibility of reagent-controlled asymmetric induction via stereoselective rhodium-catalyzed hydrogenation of β-keto enamides. Highly enantio- and diaste­reoselective formation of two stereocenters was accomplished for a number of β-aryl enamides with high yields. The developed method was merged with Pd/C-catalyzed hydrogenolysis, leading to a first catalytic method to prepare γ-arylisobutylamines, which represent a group of biologically and pharmaceutically important compounds. It is also noteworthy that the starting β-keto enamides are selectively derived from 1,3-diketones.