Acylhydrazone-based dynamic combinatorial libraries: study of the thermodynamic/kinetic evolution, configurational and coordination dynamics

Abstract

The kinetic and thermodynamic selectivity of acylhydrazone formation in dynamic combinatorial libraries (DCL) is described. Competition reactions were generated from hydrazides: isoniazid, 4-nitro-benzohydrazide, 4-dimethylamino-benzohydrazide, and nicotinic hydrazide; as well as the aldehyde derivatives: benzaldehyde and 2-pyridine-carboxaldehyde. The obtained species and the distribution of the DCLs were monitored by 1 H-NMR spectroscopy finding that those acylhydrazones containing the 4-dimethylamino-benzohydrazide are both the kinetic and thermodynamic product of their respective libraries. Configurational and coordination dynamics for some of these libraries were also investigated. The obtained results allowed the study of the redistribution of components and the amplification of one or more products using light and metal ions as physical and chemical templates, respectively.