Iron-Catalyzed Three-Component Reactions of Cyclopropanols with Alkenes and N-Heteroarenes via Ring-Opening and C-H Functionalization.

An iron-catalyzed ring-opening multicomponent reaction of cyclopropyl alcohols with alkenes and N-heteroarenes involving aryl C(sp2)-H functionalization was developed. This protocol facilitates the regioselective introduction of both the β-carbonyl moiety and an N-heteroarene group across the C═C bond of the alkene, thus allowing a straightforward, efficient, and facile access to 5-heteroarene ketones. In this process, this strategy relies on β-carbonyl alkyl radical formation from the ring-opening of cyclopropyl alcohols, addition across C═C bonds, and heteroaryl C(sp2)-H functionalization cascades. This general approach displays excellent selectivity control and broad functional-group tolerance.