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Synthesis, Structures and DFT Computational Studies of [3.1.1]Metacyclophanes Containing Benzofuran Rings
Author(s) -
Islam Md. Monarul,
Wang ChuanZeng,
Feng Xing,
Rahman Shofiur,
Georghiou Paris E.,
Alodhayb Abdullah,
Yamato Takehiko
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201803390
Subject(s) - chemistry , benzofuran , intramolecular force , alkoxy group , calixarene , reagent , hydrogen bond , proton nmr , trimethylsilyl , methyl iodide , hydrogen iodide , isocyanide , photochemistry , medicinal chemistry , stereochemistry , hydrogen , organic chemistry , molecule , alkyl
[3.1.1]Metacyclophane ([3.1.1]MCP) 6 a containing two benzofuran rings was obtained by treatment of [3.3.3]MCP‐dione 5 with trimethylsilyl iodide. The precursor 5 was synthesized using ( p ‐tolylsulfonyl)methyl isocyanide (TosMIC) as the cyclization reagent. The 1 H‐NMR spectrum of 6 a at room temperature reveals that it undergoes very fast conformational changes relative to the NMR time scale and that the phenolic hydrogen forms weak intramolecular hydrogen bonding with the oxygen of one of the benzofurans. O ‐Methylation of 6 a afforded the calixarene analogue, macrocyclic [3.1.1]MCP 7 a whose 1 H‐NMR spectrum reveals that it adopts a cone‐likeconformation in solution at room temperature and the alkoxy group is pointing above and away from the macrocyclic cavity.