Natural terphenyls: Developments since 1877

Terphenyls are aromatic hydrocarbons consisting of a chain of three benzene rings. There are three isomers in which the terminal rings are ortho-, meta-, or para-substituents of the central ring. This review covers the synthesis of terphenyls, biological activities of p-terphenyls, and biosynthesis of terphenyls. Under terphenyl synthesis, topics discussed include the general methods for the synthesis of substituted terphenyls, methods of synthesis based on dehydrogenations, and syntheses of terphenylquinones based on the methoxide-catalyzed rearrangement of grevillins, total synthesis of p-terphenyls and natural terphenyl-like scaffolds. As for the biological activities of p-terphenyls, focus is on immunosuppressants, antioxidants, neutroprotective activity, cytotoxic activity, and antithrombotic and anticoagulant activity.