Regioselective synthesis of naphthalenes from modified Baylis-Hillman adducts via a Pd-catalyzed cyclization: 5-exo-carbopalladation, C(sp3)-H activation to cyclopropane, ring-opening, and aromatization cascade

Modified Baylis-Hillman adducts having 2-bromophenyl acetonitrile moiety at the primary position underwent a Pd-catalyzed cascade reaction to provide poly-substituted naphthalene derivatives in reasonable yields. The reaction involved a sequential 5-exo-carbopalladation, C(sp3)-H activation to cyclopropane, ring-opening and concomitant aromatization processes.