Generation and capturing of arynes under mechanochemical conditions

Abstract: This thesis investigated whether or not it is possible to generate and capture arynes under mechanochemical conditions. The investigation covered mechanochemical parameters, as well as parameters known to influence aryne generation in solution such as crown ether and CsF loading. Experiments were performed in steel vessels, each equipped with a single free moving steel ball in a shaker type mill. Different reactivities were probed, including nucleophilic addition, [4+2] Diels-Alder cycloaddition, [3+2] cycloaddition and Pd-catalyzed cyclotrimerization. Acquired crude product mixtures were analysed with NMR spectroscopy, and spectra were compared to reported spectra of reactants and expected products. The results showed generation and capturing of arynes to be possible under mechanochemical conditions with borylated, as well as non-borylated aryne precursors in moderate to good yields. Regioselectivity did not appear to differ from solvent conditions since only single regioisomers were observed.