Using guanidinium groups for the recognition of RNA and as catalysts for the hydrolysis of RNA

Efficient synthesis of diarylidene octahydroacridines by one-pot multi-component tandem reactions

“…For example, octahydroacridines have been prepared by heating a mixture of aldehyde, cyclic ketone and ammonium acetate [23,24].…”

“…Finally, octahydroacridines can also be prepared through a condensation reaction of cyclic ketone enamine with formaldehyde to form bis(2-oxocycloalkyl)methane, which in turn is heated with ammonium acetate [28]. Compared to conventional heating [23,24], the reaction under microwave irradiation is very convenient and efficient and very little byproducts have been detected. Therefore, the workup procedure involves only a simple filtration of the precipitate followed by crystallization with alcohol.…”

Organophosphorus Supramolecular Chemistry Part 1. Receptors for Organophosphorus Compounds

“…It results from optimal arrangement of interacting groups on one side of the rigid scaffold. Receptors 81-83 were successfully applied as catalysts of RNA cleavage and thus might be considered as models of restriction enzymes [79,80].…”

On Facts and Artefacts: The Difficulty to Evaluate an Artificial Nuclease

“…Such artificial ribonucleases are mostly based on metal complexes [1], however, some metal-free systems are known as well [2 ± 4]. They generally consist of oligo amines [4], guanidines, or structurally analogous heterocycles [2] [3]. In recent years, we have studied the catalysis of phosphoryl-transfer reactions by guanidinium salts {3-[(guanidino)methyl]phenyl}methylguanidine (1b) and 2-[(3-{[(4,5-dihydro-1H-imidazol-2-yl)amino]methyl}phenyl)methyl]amino-4,5-dihydro-1H-imidazole (2b) [5] [6].…”

“…Here, again, the digestion of the 2',5'-substrate stopped at low levels, irrespective of enzyme concentration and reaction time (data not shown). A positively charged anion receptor such as 5b may catalyze RNA hydrolysis by electrostatic transition-state stabilization [2] [3] [7], and, while it is reasonable not to expect high levels of 3',5' selectivity from this mechanism, it cannot be excluded in a strictly logical sense. The experiments shown in Fig.…”