Total synthesis, antiprotozoal and cytotoxicity activities of rhuschalcone VI and analogs

The total syntheses of natural product rhuschalcone VI and eight analogs employing the Suzuki–Miyaura reaction are reported together with antiprotozoal activities and cytotoxicity data for some of them. The total synthesis of a potent antiplasmodial natural bichalcone, rhuschalcone VI, is described starting from simple and available resorcinol and 4-hydroxybenzaldehyde. Key steps include the solvent-free Aldol syntheses of chalcones, and the successful application of the Suzuki–Miyaura coupling reaction in the synthesis of bichalcones. The present work constitutes a general method for the rapid syntheses of a number of bichalcones related to rhuschalcone VI. Some of the bichalcones showed moderate antiprotozoal activities against Bodo caudatus, a preliminary screening system for antitrypanosomal activities, most of them with little or no cytotoxicity.