Stereoselective Synthesis and Structure of New Types of Calix[4]resorcinarenes. Complexation of Tetrakis(O,O-Phosphorus)Bridged-Calix[4]resorcinarenes with Heavy Metal Atoms

Abstract

The acid‐catalyzed (with HCl) condensation reactions of resorcinol (1) with 1‐naphthaldehyde (2) and isobutyraldehyde (3) furnished the tetrameric macrocyclic compounds 4 and 6. Detailed NMR‐investigations of the acetylated tetrameric species 5 surprisingly support a structure not in agreement with the expected all‐cis conformation. The chair conformation (C2h symmetry) of the acetylated derivative 5 was established through a crystal X‐ray diffraction study. The naphthyl substituents are arranged in trans position above and below the plane made up by the resorcinol units. The reaction of resorcinol 1 with isobutyraldehyde, in accord with expectation, led to the calix[4]resorcinaren (6). The 1H NMR spectra of compound 6 and 7 appeared at room temperature as broad signals, indicating a conformation of C2v symmetry. The reaction of the C‐methyl‐tetrakis‐P‐(chlorodioxaphosphocin)‐calix[4]resorcinarenes (8) and (10) with suitable N‐trimethylsilyl organic amines were conducted in tetrahydrofuran suspension, furnishing the P–N‐substituted calix[4]resorcinarenes (9) and (11). While in the complexation of C‐methyl‐tetrabromotetrakis‐P‐(dimethylaminodioxaphosphocin)‐calix[4]resorcinarene (13) with (tht)AuCl (tht = tetrahydrothiophene) the expected, neutral tetra‐substituted complex 15 was formed, the reaction of 13 with moist acetonitrile led to the anionic atomic framework 14. X‐ray structure determinations of the complexes 14 and 15 show that both possess the cone conformation. In the gold complex 15, the Au–Cl groups form a loose aggregate, with three Au…Cl contacts of 316–340 pm; one of the groups points towards the centre of the cone. The copper(I) complex 14 displays crystallographic mirror symmetry, with a central Cu4Cl5 unit involving tetrahedrally coordinated copper.

Multimodal switching of a redox-active macrocycle

“…2b) by the acid catalyzed condensation of resorcinol with 3,5-di-t-butyl-4-hydroxybenzaldehyde. The exclusive formation of rctt- 1 is consistent with previous reports for the synthesis of resorcinarenes from aryl aldehydes 22,23 . Phenolic hydroxyl groups of the macrocycle were selectively benzylated to give rctt- 2 .…”

Asymmetric calixarene derivatives as potential hosts in chiral recognition processes

“…In some digold-calix [4]arene complexes the gold(I) ions were shown to be mobile [15]. Other examples with calix [4]resorcinarenes have been presented [16][17][18], which are structurally very similar to calix [4]arenes. Industrial applications have been described by Perrin et al [19].…”

Synthesis of in,out-isomeric phosphite and phosphate cryptands

“…10 Its 1 H and 13 C NMR spectra are very simple and reflect the C 3v symmetry of the molecule. Most convincing, however, is the MALDI TOF peak at 1258 Da for the complex cation.…”