Efficient Macrocyclization Achieved via Conformational Control Using Intermolecular Noncovalent π-Cation/Arene Interactions

Abstract

Quinolinium salt 3 is an effective additive that acts as a conformation control element (CCE) to promote macrocyclization to form rigid cyclophanes via olefin metathesis or Glaser-Hay coupling, which do not cyclize in the absence of the additive. The additives are easily synthesized and highly modifiable and have solubility profiles which allow for simple recovery via filtration.

Macrocyclization Reactions: The Importance of Conformational, Configurational, and Template-Induced Preorganization

“…488 Collins and co-workers have described an efficient macrocyclization using intermolecular noncovalent aromatic interactions to properly preorganize the open-chain precursor 489 ( Figure 152). 489 The use of the external conformational driving element plays a crucial role favoring the formation of the supramolecular complex 491. The macrocyclic product 490 was not obtained in the absence of 488.…”

Aromatische Ringe in chemischer und biologischer Erkennung: Energien und Strukturen

“…[271] Vor Kurzem wurde gezeigt, dass Kation-p-Wechselwirkung intramolekulare Olefinmetathesen ermöglicht: Makrocyclisierungsprodukte wurden mit einem zugesetzten N-Methylchinoliniumsalz als konformatives Kontrollelement in 45-90 % Ausbeute erhalten, wogegen kein Produkt in Abwesenheit des Salzes gebildet wurde (siehe Abschnitt 3.2 für ähnliche Beobachtungen mit Perfluorarenen). [272] Wegen der Kation-p-Wechselwirkung zwischen dem Chinoliniumion und dem Aren des Substrats wird eine Seite des aromatischen Rings blockiert, und die Substituenten werden in die zur Metathese benötigte Konformation gezwungen. In derselben Weise ermöglicht das Chinolinium-Kontrollelement intramolekulare Glaser-Hay-Kupplungen mit Ausbeuten um die 40 %.…”

General Scheme for Oxidative Quenching of a Copper Bis‐Phenanthroline Photosensitizer for Light‐Driven Hydrogen Production

“…The following materials were prepared according to known literature procedures: [Co(dmgH) 2 (py) 2 ]PF 6 , [31] [Co(DOH)Br 2 ], [5f] [Co(aPPy)Br]Br, [5a] [Co(bupyrphyrin)(MeOH)Br]. [24] 1H,1'H-2,2'-biimidazole (BIm) [32] and 1H,1'H-2,2'-bibenzo [d]imidazole (BBIm) [33] were used as precursors for the synthesis of the intermediates [P 2 BIm]Br 2 , [34] [36] [MPP]PF 6 . [37] Counter [36] Spectroscopy: UV/Vis spectra were recorded on a Varian Cary 50 Scan in 1 cm quartz cuvettes and steady state luminescence spectra were recorded on a PerkinElmer LS50B in 1 cm quartz cuvettes.…”

“…[24] 1H,1'H-2,2'-biimidazole (BIm) [32] and 1H,1'H-2,2'-bibenzo [d]imidazole (BBIm) [33] were used as precursors for the synthesis of the intermediates [P 2 BIm]Br 2 , [34] [36] [MPP]PF 6 . [37] Counter [36] Spectroscopy: UV/Vis spectra were recorded on a Varian Cary 50 Scan in 1 cm quartz cuvettes and steady state luminescence spectra were recorded on a PerkinElmer LS50B in 1 cm quartz cuvettes. Electrochemistry: Electrochemical measurements were performed in nitrogen degassed DMF using [TBA]PF 6 (TBA = tetrabutylammonium) as the supporting electrolyte.…”