Diureido derivative

Very recently, interesting macrocyclic diureido derivatives 39a,b lower rim bridged by a spacer unit were reported [50]. Their oxidation with (CF3COO)3Tl led to the corresponding quinones 39c,d, potentially useful as electrochemical anion receptors. A similar upper rim bridged system 40 was shown to exhibit good shape-selective recognition abilities towards various aromatic dicarbox-ylates in DMSO [51]. The molecular mechanics force field calculations indicate... 

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