Differently substituted benzimidazoles have been synthesised from o-phenylenediamine and arylaldehydes or arylmethylene-malononitriles absorbed on silica gel. The reaction was carried out by intermittent grinding or by a microwave-assisted technique under solvent- and catalyst-free conditions giving good yields of the products.
Nanochannel-based [(CH3)2NH2]2[BaZn(TDP)(H2O)]×DMF×5H2O}n (NUC-51) is synthesized and displays a high catalytic activity on the cycloaddition reactions of epoxides with CO2 and the deacetalization-Knoevenagel condensation reaction.