Rapid Assembly of Unsymmetrically Linked Bis-heterocycles via Palladium Domino Catalysis.

A palladium-catalyzed domino reaction of alkene-tethered oxime esters is reported. This transformation uses an air-stable palladium precatalyst that initiates a Narasaka-Heck reaction, that is interrupted with a Pd(II)-promoted cyclization. Through this methodology, a novel class of unsymmetrical alkyl-linked bis-heterocycles were synthesized in yields up to 99%. The reaction is scalable up to 1.0 mmol, with simplified purification steps. This transformation expands the scope of accessible bis-heterocycles available through Narasaka-Heck reactions beyond C-H activation and direct anionic capture termination steps.