Nickel-Catalyzed Cycloaddition of Salicylic Acid Ketals to Alkynes via Elimination of Ketones

An intermolecular nickel-catalyzed addition reaction has been developed where salicylic acid ketals react with alkynes to afford substituted chromones. A mechanistic rationale is proposed, implying beta-elimination of ketone from ring strained seven-membered nickelacycle to generate a five-membered oxa-nickelacycle intermediate.