Hypervalent Iodine Based Reversible Covalent Bond in Rotaxane Synthesis

Abstract

Reversible covalent bonds play a significant role in achieving the high‐yielding synthesis of mechanically interlocked molecules. Still, only a handful of such bonds have been successfully employed in synthetic procedures. Herein, we introduce a novel approach for the fast and simple preparation of interlocked molecules, combining the dynamic bond character of bis(acyloxy)iodate(I) anions with macrocyclic bambusuril anion receptors. The proof of principle was demonstrated on rotaxane synthesis, with near‐quantitative yields observed in both the classical and “in situ” approach. The rotaxane formation was confirmed in the solid‐state and solution by the X‐ray and NMR studies. Our novel approach could be utilized in the fields of dynamic combinatorial chemistry, supramolecular polymers, or molecular machines, as well inspire further research on molecules that exhibit dynamic behavior, but owing to their high reactivity, have not been considered as constituents of more elaborate supramolecular structures.

O–I–O halogen bond of halonium ions

“…This is significant as investigations of halogen bonding applying oxygen ligands as Lewis bases have been scarce, 40 and 3c4e halogen bonding with two oxygen ligands has so far been scarcely explored. 17,51 Our study provides new insights into both halogen bonding and 3c4e bonds. Additionally, [O-I-O] + complexes are of interest for the development of new supramolecular synthons and of improved reagents for halofunctionalization and oxidation reactions.…”

Carbonyl Hypoiodites as Extremely Strong Halogen Bond Donors

“…[50] In addition to their synthesis, [27] use of structurally related anionic complexes [R−COO−I−OOC−R] − , which should be considered as the anionic‐type 3c‐4e XB complexes with two oxygen atoms as XB acceptors, [25] have been utilized as dynamic axles in the construction of rotaxanes. [51] …”

Cyclohexanohemicucurbit[8]uril Inclusion Complexes With Heterocycles and Selective Extraction of Sulfur Compounds From Water

“…Hemicucurbiturils, formed in templated single-step oligomerization reactions ( Kaabel and Aav, 2018 ), are single-bridged cucurbituril-type macrocycles ( Andersen et al, 2018 ; Lizal and Sindelar, 2018 ; Xi et al, 2018 ) that bear an electron-deficient hydrophobic cavity. The latter grants these macrocycles the ability to encapsulate anions ( Buschmann et al, 2005 ; Cucolea et al, 2016 ; Kaabel et al, 2017 ; Assaf and Nau, 2018 ; Reany et al, 2018 ; Vázquez and Sindelar, 2018 ; Andersen et al, 2019 ; Kandrnálová et al, 2019 ; Valkenier et al, 2019 ; Maršálek and Šindelář, 2020 ); in addition, the formation of complexes with acids and some neutral species has been reported in the previous work. In particular, unsubstituted hemicucurbit[ n ]urils ( n = 6, 12) bind phenol derivatives ( Jin et al, 2016a ; 2016b ) and ferrocene ( Jin et al, 2017 ), and cyclohexanohemicucurbit[ n ]urils cycHC [ n ] ( n = 6, 8, 12) ( Li et al, 2009 ; Aav et al, 2013 ; Prigorchenko et al, 2015 , 2019 ; Mishra et al, 2020 ) form external complexes with both inorganic and organic acids ( Öeren et al, 2014 ; Ustrnul et al, 2019 , 2021 ).…”