Synthesis, Structure, and Molecular Recognition of S₆‐ and (SO₂)₆‐Corona[6](het)arenes: Control of Macrocyclic Conformation and Properties by the Oxidation State of the Bridging Heteroatoms

Abstract

We report herein the synthesis, structure, and molecular recognition of S6 - and (SO2 )6 -corona[6](het)arenes, and demonstrate a unique and efficient strategy of regulating macrocyclic conformation and properties by adjusting the oxidation state of the heteroatom linkages. The one-pot nucleophilic aromatic substitution reaction of 1,4-benzenedithiol derivatives, biphenyl-4,4'-dithiol and 9,9-dipropyl-9H-fluorene-2,7-dithiol with 3,6-dichlorotetrazine afforded S6 -corona[3]arene[3]tetrazines. These compounds underwent inverse-electron-demand Diels-Alder reaction with enamines and norbornadiene to produce S6 -corona[3]arene[3]pyridazines. Facile oxidation of sulfide linkages yielded (SO2 )6 -corona[3]arene[3]pyridazines. All corona[6](het)arenes adopted generally hexagonal macrocyclic ring structures; however, their electronic properties and conformation could be fine-tuned by altering the oxidation state of the sulfur linkages. Whereas (SO2 )6 -corona[3]arene[3]pyridazines were electron-deficient, S6 -corona[3]arene[3]pyridazines acted as electron-rich macrocyclic hosts that recognized various organic cations in both aqueous and organic solutions.

Synthesis, Structure, and Anion Binding Properties of Electron‐Deficient Tetrahomocorona[4]arenes: Shape Selectivity in Anion–π Interactions

“…On the basis of nucleophilic aromatic substitution reaction, we have established highly efficient one‐pot reaction strategy and stepwise fragment coupling approach to construct corona[ n ]arenes ( n =5, 6, 8). Post‐macrocyclization chemical manipulation methods have also been developed to synthesize functional corona[ n ]arenes. Corona[ n ]arenes have been demonstrated to be versatile and fascinating host molecules to complex anions, cations, and neutral guest species …”

“…Post‐macrocyclization chemical manipulation methods have also been developed to synthesize functional corona[ n ]arenes. Corona[ n ]arenes have been demonstrated to be versatile and fascinating host molecules to complex anions, cations, and neutral guest species …”

Dancing with Sulfur: Simple Preparation and Properties ofThiacalix[n]thiophene Derivatives

“…In fact, some cyclic thioethers having electron decient aromatic rings, and which are also analogues of thiacalix[n]arene, had been successfully prepared by a nucleophilic substitution based on this strategy. 7,8 After several attempts, we found that C S bond formation using diboromothiophene derivatives and tributyltinsul de ((Bu 3 Sn) 2 S) in the presence of Pd(PPh 3 ) 4 successfully gave thiacalix[n]thiophenes (n 4 6) (Table1). While this kind of coupling was originally developed by Kosugi and Migita in 1985 for the preparation of symmetrical/nonsymmetrical diarylsul des, 27 it was found that cyclic compounds were obtained preferentially depending on the exact conditions applied.…”

Synthesis, Structure, and Anion Binding Properties of Electron‐Deficient Tetrahomocorona[4]arenes: Shape Selectivity in Anion–π Interactions

“…On the basis of nucleophilic aromatic substitution reaction, we have established highly efficient one-pot reaction strategy [8][9][10][11][12][13] and stepwise fragment coupling approach [14,15] to construct corona[n]arenes (n = 5, 6, 8). Post-macrocyclization chemical manipulation methods [9-10, 13, 14] have also been developed to synthesize functional corona[n]arenes.Corona- [n]arenes have been demonstrated to be versatile and fascinating host molecules to complex anions,c ations,a nd neutral guest species.…”

“…Post-macrocyclization chemical manipulation methods [9-10, 13, 14] have also been developed to synthesize functional corona[n]arenes.Corona- [n]arenes have been demonstrated to be versatile and fascinating host molecules to complex anions,c ations,a nd neutral guest species. [8][9][10][13][14][15][16] Anion-p interactions are now recognized as general and useful non-covalent bond attraction force in host-guest chemistry. [17,18] To fabricate selective anion receptors on the principle of typical anion-p interactions,w er ecently prepared corona[4]arene [2]tetrazines and corona [3]arene- [3]tetrazines in which electron deficient tetrazine moieties are face-to-face paralleled and are aligned in an equilateral triangle,r espectively.…”