Organic Chemistry

A Concise Synthesis of a Methyl Ester 2-Resorcinarene: A Chair-Conformation Macrocycle

Abstract

Anions are important hydrogen bond acceptors in a range of biological, chemical, environmental and medical molecular recognition processes. These interactions have been exploited for the design and synthesis of ditopic resorcinarenes as the hydrogen bond strength can be tuned through the modification of the substituent at the 2-position. However, many potentially useful compounds, especially those incorporating electron-withdrawing functionalities, have not been prepared due to the challenge of their synthesis: their incorporation slows resorcinarene formation that is accessed by electrophic aromatic substitution. As part of our broader campaign to employ resorcinarenes as selective recognition elements, we need access to these specialized materials, and in this article we report a straightforward synthetic pathway for obtaining a 2-(carboxymethyl)-resorcinarene, and resorcinarene esters in general. We discuss the unusual conformation it adopts, and propose that this arises from the electron-withdrawing nature of the ester substituents that renders them better hydrogen bond acceptors than the phenols, ensuring that each of those acts as a donor only. DFT calculations show that this conformation arises as a consequence of the unusual configurational isomerism of this compound and interruption of the archetypal hydrogen bonding by the ester functionality.

Version notes

Version 1.0

Content

Thumbnail image of 2021-03-20 Reynolds et al.pdf

Supplementary material

Thumbnail image of SI 2021-03-20 Reynolds et al.pdf
SI 2021-03-20 Reynolds et al
Thumbnail image of Video S1. C2_Bowl.mp4
Video S1. C2 Bowl
Thumbnail image of Video S2. C2_Chair.mp4
Video S2. C2 Chair
Thumbnail image of Video S3. C4v_Bowl.mp4
Video S3. C4v Bowl
Thumbnail image of Video S4. C4v_Chair.mp4
Video S4. C4v Chair
Thumbnail image of Video S5. Crystal structure.mp4
Video S5. Crystal structure
Thumbnail image of Video S6. Overlay.mp4
Video S6. Overlay
Thumbnail image of File S1 GasPhase_C2_bowl.txt
File S1 GasPhase C2 bowl
Thumbnail image of File S2 GasPhase_C2_chair.txt
File S2 GasPhase C2 chair
Thumbnail image of File S3 GasPhase_C4v_bowl.txt
File S3 GasPhase C4v bowl
Thumbnail image of File S4 GasPhase_C4v_chair.txt
File S4 GasPhase C4v chair
Thumbnail image of File S5 CHCl3_C2_bowl.txt
File S5 CHCl3 C2 bowl
Thumbnail image of File S6 CHCl3_C2_chair.txt
File S6 CHCl3 C2 chair
Thumbnail image of File S7 CHCl3_C4v_bowl.txt
File S7 CHCl3 C4v bowl
Thumbnail image of File S8 CHCl3_C4v_chair.txt
File S8 CHCl3 C4v chair