Some different approaches have been developed in order to determine the most efficient preparation of bis-benzimidazoles 1a - f under solvent-free conditions. All of the selected methods are simple, avoiding heating with corrosive mineral acids. Heating of the reactants on a sand bath method appears to have higher efficiency.
Complexation of Imidazopyridine-Based Cations with a 24-Crown-8 Ether Host: [2]Pseudorotaxane and Partially Threaded Structures
作者:Surisadai I. Moreno-Olivares、Ruy Cervantes、Jorge Tiburcio
DOI:10.1021/jo401701m
日期:2013.11.1
host–guest complex geometry: (i) for linear guests with relatively bulky groups (i.e., a benzyl substituent), the 1,2-bis(benzimidazole)ethane motif is favored, leading to a fully threadedcomplex with a [2]pseudorotaxane geometry; (ii) for small substituents, such as −H and −CH3 groups, regardless of the guest shape, the pyridinium motifs are preferred, leading to external partially threadedcomplexes in