Kinetic studies of copper-catalysed conjugate addition reactions with organoaluminium reagents and their implementation towards enantioselective synthesis of quinolone derivatives

Conjugate addition reactions with organometallic reagents have been extensively utilised in the synthesis of a wide range of diverse molecules. Despite this, certain phenomena regarding the mechanistic pathway of the reaction remain unexplored. As such, challenges associated with certain synthetic transformations involving this class of reaction require extensive research to expand our understanding on a molecular level and implement this understanding in a functional capacity. Here we present studies involving the elucidation of the mechanistic pathway for copper-catalysed conjugate reactions of organoaluminium reagents. This involved detailed kinetic studies concerning the formation of an active complex between an α,β-unsaturated enone and triethylaluminium, its involvement in the formation of a proposed transition state for the conjugate addition reaction and discovering the stoichiometry of this transition state. Additionally, the development of a methodology towards the enantioselective copper-catalysed conjugate addition of organoaluminium reagents to quinolone substrates was performed in efforts to access a series of diverse, biologically-active scaffolds. The primary aim was to perform addition with alkyl- and alkenylaluminium reagents to these quinolone substrates; these would afford novel products which have not been synthesised with existing methodology