Subcomponent Self‐Assembly of a Cyclic Tetranuclear Fe^II Helicate in a Highly Diastereoselective Self‐Sorting Manner.

Anhäuser, Jana; Puttreddy, Rakesh; Glanz, Lukas; Schneider, Andreas; Engeser, Marianne; Rissanen, Kari; Lützen, Arne

An enantiomerically pure diamine based on the 4,15‐difunctionalized [2.2]paracyclophane scaffold and 2‐formylpyridine self‐assemble into an optically pure cyclic metallosupramolecular Fe4L6 helicate upon mixing with iron(II) ions in a diastereoselective subcomponent self‐assembly process. The cyclic assembly results from steric strain that prevents the formation of a smaller linear dinuclear triple‐stranded helicate, and hence, leads to the larger strain‐free assembly that fulfils the maximum occupancy rule. Interestingly, use of the racemic diamine also leads to a racemic mixture of the homochiral cyclic helicates as the major product in a highly diastereoselective narcissistic chiral self‐sorting manner given the fact that the assembly contains ten stereogenic elements, which can in principle give rise to 149 different diastereomers. The metallosupramolecular aggregates could be characterized by NMR, UV/Vis and CD spectroscopy, mass spectrometry, and X‐ray crystallography.

ENANTIOMERIC purity; MASS spectrometry; COURTESY; DIASTEREOISOMERS; SUPRAMOLECULAR chemistry; RACEMIC mixtures; CELL separation; X-ray crystallography

Chemistry - A European Journal, 2019, Vol 25, Issue 53, p12294

0947-6539

Academic Journal

10.1002/chem.201903164