Preparation, Isolation and Structural Characterization of Transient Species of DBU. Their Application as Green Reagents

A state of the art synthesis and isolation procedure is developed for 17 different transient species of DBU. The structure of these transient species, which are thoroughly confirmed from various spectral data, is different from their parent compound DBU and provides emphatic support in favor of formation of transient species in various DBU catalyzed reactions. DFT studies of N-sulphonylTransient species of DBU has given a new insight of an alternate transient species in addition to the normal species which provides a new scope for further investigation. The applications of three Transient species as direct reagents for base free functionalizations are also documented. They can be directly employed as Eco-friendly reagents in water as solvent. The Lewis base can be recovered and reused for the preparation of Transient species after the reaction. The influence of N-substituent on the chemical shift of these transient species also documented.