Resorc[4]arenes as preorganized synthons for surface recognition and host-guest chemistry

This chapter is aimed at providing an overview of the up-to-now published literature on resorc[4]arene macrocycles exploited as artificial receptors for surface recognition and host-guest chemistry. A concise illustration of the main synthetic strategies developed to afford the resorc[4]arene scaffold is followed by a report on the principles of the investigation of recognition phenomena by nuclear magnetic resonance (NMR), in particular the study of protein-small molecule interactions. Emphasis will be placed on the literature taken largely from our own works on the inhibition of chymotrypsin by suitable N-linked peptidoresorc[4]arenes. Then, the attention was moved towards host-guest studies relying on the entrapment of nitrosonium (NO+) cation inside the cavities of ad hoc functionalized resorc[4]arenes, which yielded both complexes and covalent products. Finally, some recent intriguing resorc[4]arene architectures built up by olefin metathesis reaction occurring between side chains ending with vinylidene groups are presented.