Nickel-Catalyzed Domino Heck-Type Reactions Using Methyl Esters as Cross-Coupling Electrophiles

While esters are frequently used as traditional electrophiles in substitution chemistry, their application in cross-coupling chemistry is still in its infancy. This work demonstrates that methyl esters can be used as coupling electrophiles in Ni-catalyzed Heck-type reactions through the challenging cleavage of the C(acyl)-O bond under relatively mild reaction conditions at either 80 or 100 degrees C. With the sigma-Ni-II intermediate generated from the insertion of acyl Ni-II species into the tethered C=C bond, carbonyl-retentive products were formed by domino Heck/Suzuki-Miyaura coupling and Heck/reduction pathways when organoboron and mild hydride nucleophiles are used.