Abstract
Radical cascade cyclization reactions provide an efficient method for the construction of polycyclic
architectures with multiple stereogenic centers. However, achieving enantioselectivity control of this type
of reaction is a challenging task. Here, we report an enantioselective cyclization of polyfunctional substrates
containing cyclopropyl ketone and alkyne units, wherein the stereochemical outcome is directed by a chiral
Ti(salen) catalyst. This transformation was proposed to proceed via a radical cascade process involving the
reductive ring-opening of the cyclopropyl ketone followed by two annulation events entailing cyclization
of the ensuing alkyl radical onto the alkyne and subsequent addition of the incipient vinyl radical to the
Ti(IV)-enolate.