Racemic 4,12‐difunctionalized [2.2]paracyclophanes were synthesized and successfully resolved by (recycling) HPLC on a stationary CHIRALPAK IA phase at a semipreparative scale. Their absolute configurations were determined by X‐ray crystal structure analysis and/or by comparison of their specific optical rotations with literature data. These are valuable functionalized C2‐symmetric building blocks for the formation of more sophisticated V‐shaped, chiral molecular architectures, as demonstrated by some exploratory transformations.

The first reported twisted bis-lactam, a racemic Tröger's base (TB) analogue (2), was resolved into its enantiomers on a chiral stationary phase HPLC column. The absolute configuration of (+)-2 was determined to be (R,R)-2 by comparing experimental and calculated vibrational circular dichroism (VCD) and electronic circular dichroism (ECD) spectra. The absolute configuration of (-)-2 was determined by comparing experimental and calculated electronic circular dichroism (ECD) spectra. The corresponding theoretical spectra were calculated using the lowest energy conformation of (R,R)-2 and (S,S)-2 at the B3LYP/6-31G(d,p) level of theory. The absolute configuration of (+)-2 was also determined to (R,R)-2 by anomalous X-ray diffraction (AXRD) in a chiral space group P212121 using Cu-irradiation resulting in a very low Flack parameter of -0.06(3), despite the heaviest element being an oxygen atom, thus unambiguously confirming the results from the spectroscopic studies. We conclude that, for the Tröger's base (TB) analogue (2), we may rank the reliability of the individual methods for AC determination as AXRD ≫ VCD > ECD, while the synergy of all three methods provides very strong confidence in the assigned ACs of (+)-(R,R)-2 and (-)-(S,S)-2.

SummaryA Tröger's base-derived racemic bis(1,10-phenanthroline) ligand (rac)-1 and a bis(2,2'-bipyridine) ligand with a central 1,3-diethynylbenzene unit 2 were synthesized. Each of these ligands acts as a multivalent entity for the binding of two copper(I) ions. Upon coordination to the metal ions these two ligands undergo selective self-assembly into heteroleptic dinuclear metallosupramolecular kites in a high-fidelity social self-sorting manner as evidenced by NMR spectroscopy and mass spectrometry.

Aryl iodides are superior coupling partners in crosscoupling reactions compared to the corresponding chlorides or bromides. Unfortunately, the iodides are much more expensive, if commercially available at all, than the other halides. Thus, it is often mandatory to transform the available bromides into the corresponding iodides. The copper-catalyzed aromatic Finkelstein reaction turned out to be the method of choice to prepare a number of highly functionalized iodo(het)aryls, including pyridines, 2,2′-bipyridines, and chiral compounds.

Chiral concave imidazolinium salts 4·Cl– with different ring sizes were synthesized as precursors of chiral concave N‐heterocyclic carbenes, starting from di‐ortho‐substituted anilines 5 and 2,7‐disubstituted aminonaphthalenes 6. The terminal alkene groups of the substituents were cyclized by ring‐closing metathesis to give bimacrocyclic axially chiral concave imidazolinium salts 14·Cl–, and, after hydrogenation of the double bonds, 4·Cl–. The overall yields of bimacrocycles 4b·Cl– and 4c·Cl– were 54 and 39 %, starting from amino‐substituted arenes 5 and 6, respectively. Racemic mixtures of the three concave NHC precursors 4a–c·Cl– were separated by chiral HPLC techniques, and their absolute stereochemistry was assigned by comparison of simulated and experimental CD spectra.