Development Of Novel Multicomponent Approaches Towards 1,3-benzodiazepines And AIE-active O,O-chelated Boron Complexes

Multicomponent reactions(MCRs)have been extensively applied in many research fields that include general synthetic methodology,synthesis of natural products,medicinal chemistry,drug development and material science.The broad synthetic application of MCRs is based on a number of attractive features that include high step and atom economy,robustness,mild reaction conditions,good chemical selectivity and simple reaction settings.This thesis focuses on the application of multicomponent reactions for the construction of medium-sized nitrogen-containing heterocycles and AIE-active O,O-chelated boron complexes.The original research data presented in this thesis is divided in three parts.The first part deals with the synthesis of 1,3-benzodiazepine core from A3-coupling-derived propargylamines and ortho-bromophenylisocyanates.The developed synthetic sequence involves the addition of propargylamine to isocyanate followed by palladium-catalyzed intramolecular alkyne hydroarylation that could be accomplished in a stepwise or one-pot manner.The second part continues the exploration of O,O-chelated boron complexes that were prepared through a four-component Ugi reaction followed by complexation of the resulting 1,3-dicarbonyl compounds with boron trifluoride diethyl etherate.A much broader series of compounds was synthesized as compared to the previous study.The optical properties of all novel compounds were investigated by UV/Vis spectroscopy and spectrofluorometry in dichloromethane solution and in solid state.Many of these new compounds showed pronounced aggregation-induced emission(AIE)characteristics.The third part outlines our preliminary attempts to conduct an enantioselective fluorination of the glyoxal-derived Ugi adducts using quinine derivative and an electrophilic fluorination reagent combination.