Pd-Catalyzed Direct Arylations of Heteroarenes with Polyfluoroalkoxy-Substituted Bromobenzenes

The reactivity of di-, tri- and tetra-fluoroalkoxy-substituted bromobenzenes in the direct arylation of 5-membered ring heteroarenes using palladium catalysis was explored. High yields in arylated heteroarenes were obtained using only 1 mol-% of Pd(OAc)(2)catalyst with KOAc as an inexpensive base. Similar yields were obtained witho/m/ptrifluoromethoxy-,o/pdifluoromethoxy-, and tetrafluoroethoxy-substituents on the aryl bromide. A bromo-substituted difluorobenzo[d][1,3]dioxole was successfully coupled. The major side-products of the reaction are HBr/KOAc. Therefore, this synthetic scheme is very attractive for the access to such polyfluoroalkoxy-containing arylated heteroaromatics in terms of cost, simplicity, and low environmental impact, compared to reactions involving arylation of heteroarenes with bromophenols followed by polyfluoroalkylation.