Functionalized 3,3′,5,5′‐Tetraaryl‐1,1′‐Biphenyls: Novel Platforms for Molecular Receptors

Abstract

AbstractThis paper describes the development of novel aromatic platforms for supramolecular construction. By the Suzuki cross‐coupling protocol, a variety of functionalized m‐terphenyl derivatives were prepared (Schemes 1–4). Macrolactamization of bis(ammonium salt) (S,S)‐6 with bis(acyl halide) 7 afforded the macrocyclic receptor (S,S)‐2 (Scheme 1), which was shown by 1H‐NMR titration studies to form ‘nesting' complexes of moderate stability (Ka between 130 and 290 M−1, 300 K) with octyl glucosides 13–15 (Fig. 2) in the noncompetitive solvent CDCl3. Suzuki cross‐coupling starting from 3,3′,5,5′‐tetrabromo‐1,1′‐biphenyl provided access to a novel series of extended aromatic platforms (Scheme 5) for cleft‐type (Fig. 1) and macrotricyclic receptors such as (S,S,S,S)‐1. Although mass‐spectral evidence for the formation of (S,S,S,S)‐1 by macrolactamization between the two functionalized 3,3′,5,5′‐tetraaryl‐1,1′‐biphenyl derivatives (S,S)‐33 and 36 was obtained, the 1H‐ and 13C‐NMR spectra of purified material remained rather inconclusive with respect to both purity and constitution. The versatile access to the novel, differentially functionalized 3,3′,5,5′‐tetrabromo‐1,1′‐biphenyl platforms should ensure their wide use in future supramolecular construction.