An efficient route to biscardanol derivatives and cardanol-based porphyrins via olefin metathesis

Ru-catalyzed olefin metathesis has been successfully applied to the synthesis of biscardanol derivatives and cardanol-based porphyrins. Using Hoveyda–Grubbs catalyst (C627), the reactions were performed with various cardanol derivatives (2, 5, 7, and 9) to make novel biscardanol derivatives. With the use of the second-generation Grubbs catalyst (C848) and Ti(OiPr)4, the ring-closing metathesis of cardanol-based porphyrin 11 was carried out to afford cyclic cardanol-based porphyrin derivative 12.