Organocatalysis of c?￡/c?￡N and C?￡C/ C?￡N exchange in dynamic covalent chemistry

摘要

The reversibly formed C?￡N bond plays a very important role in dynamic covalent chemistry and the C?￡N/C?￡N exchange of components between different imine constituents to create dynamic covalent libraries has been extensively used. To facilitate diversity generation, we have investigated an organocatalyzed approach, using L-proline as catalyst, to accelerate the formation of dynamic libraries of [n×n] imine components. The organocatalysis methodology has also been extended, under somewhat modified conditions, to reversible C?￡C/C?￡N exchange processes between Knoevenagel derivatives of barbituric acid and imines, allowing for the generation of increased diversity.