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Novel 4,4′‐Bipyridinium‐Based Cationic Mono‐ and Bicyclic Cyclophanes
Author(s) -
Rajakumar Perumal,
Srinivasan Kannupal
Publication year - 2003
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200390183
Subject(s) - cyclophane , chemistry , cationic polymerization , bicyclic molecule , intramolecular force , redox , stereochemistry , polymer chemistry , medicinal chemistry , organic chemistry , crystal structure
The intra‐annularly functionalised tetracationic cyclophanes 3a − b were synthesised from the corresponding m ‐terphenyl dibromides and 4,4′‐bipyridine by a simple quaternisation methodology. An intra‐annularly linked tetracationic cyclophane 10 was synthesised in three steps and it possesses a concave structure and novel intramolecular CT interactions. Synthesis of the tetracationic cyclophanes 13 , 16a and 16b containing carbonyl groups was accomplished from the corresponding carbonyl dibromides and 4,4′‐bipyridine. Sixfold coupling of a tricarbonyl tribromide with 4,4′‐bipyridine afforded a rare hexacationic cyclophane 18 . The cyclophanes 3a and 3c form CT complexes with a bis(1 H ‐indol‐3‐yl)(phenyl)methane compound while the cyclophane 13 forms CT complexes with 1,4‐dimethoxybenzene and indole. Electrochemical parameters were obtained for all the cyclophanes. They exhibit two sets of redox peaks and most of them are quasireversible. The smallest‐cavity cyclophane 13 has the lowest reduction potentials in the series. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)