Fagnou and coworkers reported a Pd-catalyzed benzylation reaction of a variety of aromatic heterocycles, including thiazoles, thiophenes, indolizines, imidazopyrimidines, triazoles, oxazoles, and furans. Traditional methods for this transformation involve either Friedel-Crafts alkylation (requires strong Lewis or Bronsted acids and invariably precludes use of electron-deficient substrates) or deprotonation and addition of an electrophile (in both methods protection of acid- and base-sensitive functionalities is necessary, respectively). In this Pd-catalyzed process, benzylic chlorides are the most optimal electrophiles and in the presence of Pd(OPiv)₂, 2-diphenylphosphino-2'-(N,N-dimethylamino)biphenyl, Cs₂CO₃, and PivOH, a plethora of substrates are converted to the desired functionalized heterocycles in good to excellent yield. As expected, the method allows for increased functional group tolerance in the conversion of acid and base-sensitive substrates to their benzylated derivatives and selectivity was observed for reaction at the benzylic chloride over the aryl chloride in several instances.

Lapointe, D.; Fagnou, K. Org. Lett. ASAP.