A chiral macrocycle for the stereoselective synthesis of mechanically planar chiral rotaxanes and catenanes

The Final Stereogenic Unit of [2]Rotaxanes: Type 2 Geometric Isomers

“…Our simple, first-principles approach has allowed us to unambiguously identify and define all the possible conditional stereogenic units of rotaxanes and catenanes and confirm that, now that a previously overlooked MGI-2 rotaxane stereochemistry has been found, the pantheon of unique stereogenic units is complete. Based on this analysis, methods exist to stereoselectively synthesize all conditional mechanical stereogenic units of [2]catenanes and [2]rotaxanes apart from MGI-2 rotaxanes; although until 2014, chiral stationary phase high-performance liquid chromatography (HPLC) was required to produce enantioenriched samples of mechanically chiral molecules since this time, methodologies for the stereoselective synthesis of MPC ,,, and MAC catenanes and rotaxanes have been disclosed. Similarly, the first stereoselective synthesis of MGI-1 rotaxanes was reported in 2005 using calixarene rings, and since then many examples based on cone-shaped macrocycles, and more recently simple prochiral rings, , have been reported.…”

“…Now that all of the mechanical stereogenic units of simple [2]catenanes and [2]rotaxanes have been delineated and concepts developed to allow their stereoselective synthesis, − ,− , it is reasonable to propose that, 62 years after such systems were first discussed, we have finally reached the end of the beginning of the study of mechanical stereochemistry. Such molecules have already been used as the basis of molecular machines, enantioselective sensors and catalysts, and chiroptical switches, work which will only accelerate as methods to synthesize them improve.…”

Mechanically interlocked luminescent molecules

“…The development of MILMs based on more complex mechanically interlocked structures promises to produce better optical properties and stabilities. Several complex MIMs have been synthesized already without relying on complex synthetic methods, [134][135][136] and the field has benefited from a large number of novel template-assisted synthetic methods. Furthermore, most control methods for tunable MILMs are chemical in nature, whereas reports using environmentally friendly stimuli such as light, mechanical force, and temperature are scarce.…”

A Platform Approach to Cleavable Macrocycles for the Controlled Disassembly of Mechanically Caged Molecules

“…We initially set out to incorporate an o ‐benzylic ether‐carbamate unit, as previously used by Papot and co‐workers, [18] in a bipyridine‐containing macrocycle suitable for the active template [24] Cu‐mediated alkyne‐azide cycloaddition (AT‐CuAAC [25] ) reaction [26] such that late stage attachment of the trigger unit was possible. Accordingly, we synthesized carboxylic acid macrocycle 1 a using a concise Ni‐mediated strategy [27] .…”