Cooperative catalysis approach to intramolecular hydroacylation

Enantioselective synthesis of polycyclic nitrogen heterocycles by Rh-catalyzed alkene hydroacylation: constructing six-membered rings in the absence of chelation assistance

Catalytic, enantioselective hydroacylations of N-allylindole-2-carboxaldehydes and N-allylpyrrole-2-carboxaldehydes are reported. In contrast to many alkene hydroacylations that form six-membered rings, these annulative processes occur in the absence of ancillary functionality to stabilize the acylrhodium(III) hydride intermediate. The intramolecular hydroacylation reactions generate 7,8-dihydropyrido[1,2-a]indol-9(6H)ones and 6,7-dihydroindolizin-8(5H)-ones in moderate to high yields with excellent enantioselectivities.

Rhodium-catalyzed sequential allylic amination and olefin hydroacylation reactions: enantioselective synthesis of seven-membered nitrogen heterocycles

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.

Enantioselective hydroacylation of N-vinylindole-2-carboxaldehydes

We report rhodium-catalyzed hydroacylations of N-vinylindole-2-carboxaldehydes that form chiral, non-racemic 2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-ones in high yields with excellent enantioselectivities.