Investigating the diastereoselective synthesis of a macrocycle under Curtin-Hammett control.

This work sheds new light on the stereoselective synthesis of chiral macrocycles containing twisted aromatic units, valuable π-conjugated materials for recognition, sensing, and optoelectronics. For the first time, we use the Curtin-Hammett principle to investigate a chiral macrocyclisation reaction, revealing the potential for supramolecular π-π interactions to direct the outcome of a dynamic kinetic resolution, favouring the opposite macrocyclic product to that expected under reversible, thermodynamically controlled conditions. Specifically, a dynamic, racemic perylene diimide dye (1 : 1 P  :  M ) is strapped with an enantiopure ( S )-1,1'-bi-2-naphthol group ( P -BINOL) to form two diastereomeric macrocyclic products, the homochiral macrocycle ( PP ) and the heterochiral species ( PM ). We find there is notable selectivity for the PM macrocycle (dr = 4 : 1), which is rationalised by kinetic templation from intramolecular aromatic non-covalent interactions between the P -BINOL π-donor and the M -PDI π-acceptor during the macrocyclisation reaction.