Synthesis of a C1-symmetric Box macrocycle and studies towards active-template synthesis of mechanically planar chiral rotaxanes

Coordinating Ability of Anions, Solvents, Amino Acids, and Gases towards Alkaline and Alkaline‐Earth Elements, Transition Metals, and Lanthanides

“…To avoid competition of solvent (DMF) with a macrocyclic ligand toward a Pd catalyst, it was replaced by chloroform, obtaining a better conversion in an oxidative Heck reaction . In the one‐pot reduction of olefin and ketone groups by a copper‐phosphine catalyst, full reduction of unsaturated ketones occurs only in solvents with coordinating ability index of −0.4 or higher .…”

“…To avoid competition of solvent (DMF) with am acrocyclic ligandt oward a Pd catalyst,i tw as replaced by chloroform, obtainingabetter conversion in an oxidative Heck reaction. [49] In the one-pot reduction of olefin and ketone groups by a copper-phosphine catalyst, full reduction of unsaturated ketones occurs only in solvents with coordinating ability index of À0.4 or higher. [50] To prepare heterogeneousc atalysts with good enantioselectivity that can be used in the cyclopropanation of styrene, Cu II ions were incorporated in mesocellular foam silicas, and treated with solutions of ac hiral tert-butylazabis(oxazoline) in an HPLC column.…”

Chiral Catenanes and Rotaxanes: Fundamentals and Emerging Applications

“…A critical breakthrough in accessing enantiopure mechanically chiral rotaxanes was achieved in the elegant work of Bordoli and Goldup (Figure ) . Using a CuAAC “click”‐active metal template synthesis, they constructed rotaxane 24 from directional macrocycle 21 and two half threads—achiral alkyne 22 and the other enantiopure azide 23 .…”

“…Acritical breakthrough in accessing enantiopure mechanically chiralr otaxanes wasa chieved in the elegantw ork of Bordoli and Goldup (Figure 16). [39,42] Using aC uAAC" click"-active metal templates ynthesis, [43] they constructed rotaxane 24 from directional macrocycle 21 and two half threads-achiral alkyne 22 and the othere nantiopure azide 23.T he diastereomers of 24 weref ormedi na ne ssentially 1:1r atio, butc rucially they could be separated by standard flash chromatography.S ubsti- The stereochemical labels R mp and S mp are assigned thus:View the rotaxane along its axle from the highest priority atom in the axle (A1) to that atom's highest priorityn eighbour (A2). If in the macrocyclethe highestp riority neighbour (M2)isd isposedclockwise from the highest priority atom (M1), then the stereochemical label is R mp ;ifi ti sd isposed anticlockwise thent he label is S mp .…”

Donor-acceptor rotaxanes with tetracationic cyclophane ring

“…Rotaxanes 1,2 are an interesting area of supramolecular systems, they belong to the class of mechanically interlocked molecules (MIMs) 3,4 together with catenanes 5,6 and daisy chains, 7 and are promising for the design of molecular machines and devices, 8,9 as well as of new materials with special properties. 10 In view of the presence of pyridinium quaternary groups in their structure, rotaxanes may be divided into those incorporating pyridinium units in the thread 11,12 and those with a tetracationic cyclophane ring.…”