Efficient copper-catalyzed cross-coupling of 1-Boc-piperazine with aryl iodides and its application in the synthesis of trazodone

A convenient and practical strategy is developed for the cross-coupling of N-Boc protected piperazines with aryl iodides using CuBr/1,1′-bi-2-naphthol as the catalyst and K3PO4 as the base. The protocol affords N-arylated piperazine products in moderate to good yields under the optimized conditions. The application of this catalytic system to the synthesis of trazodone is also successfully demonstrated using commercially available substrates.