Enolate generation under hydrogenation conditions: Catalytic Aldol cycloreduction of keto-enones

[GRAPHIC] Formal heterolytic activation of elemental hydrogen under Rh catalysis enables the reductive generation of enolates from enones under hydrogenation conditions. Enolates generated in this fashion participate in catalytic C-C bond formation via carbonyl addition to aldehyde and, as demonstrated in this account, ketone partners. Notably, the use of appendant dione partners enables diastereoselective formation of cycloaidol products possessing 3-stereogenic centers, including 2-contiguous quaternary centers.