Pd-catalyzed intramolecular addition of active methylene compounds to alkynes with subsequent cross-coupling with (hetero)aryl halides.
Aleksandra BłockaPaweł WoźnickiMarek StankevičWojciech ChaładajPublished in: RSC advances (2019)
We report an efficient protocol for tandem Pd-catalyzed intramolecular addition of active methylene compounds to alkynes, followed by subsequent cross-coupling with (hetero)aryl bromides and chlorides. The reaction proceeds under mild conditions, providing excellent functional group tolerance, including unprotected OH, NH 2 groups, enolizable ketones, or a variety of heterocycles. Mechanistic studies point towards a catalytic cycle involving oxidative addition, intramolecular nucleophilic addition to the Pd(ii)-activated alkyne, and reductive elimination, with 5- exo-dig cyclization being the rate limiting step.