Theoretical investigation on Friedel−Crafts reaction followed by rear-rangement/aromatization or ring-opening delivering benzoheterocycle and polycyclic alcohol, biaryl carboxylic acid

Our DFT calculations provide the first theoretical investigation on CF3SO3H-promoted [1,5]Friedel−Crafts of 2-aryoxy-1,3-indandione and base-facilitated [1,6]Friedel−Crafts of 1,3-dicarbonyl. An intramolecular [1,5]Friedel−Crafts addition took place by activating carbonyl through H bridge with CF3SO3H. The resulting tertiary alcohol underwent dehydration producing reactive carbocation, which instigated a cascade of carbox-yl group formation, ring-opening via C−C bond dissociation and C=C bond formation realizing aromatization. The product 3-aryl-2-benzo was yielded with recovered CF3SO3H. The electron-rich phenoxy group was deprotonated by HO- forming water. The initial nucleophilic addition to spatial-adjacent carbonyl afforded dieneone. It isomerized to the first product polycyclic alcohol. Then carboxylation occurred via hydroxyl shift followed by ring-opening aromatization to the second product biaryl carboxylic acid. The positive solvation effect is suggested by decreased absolute and activation energies in solution compared with in gas. These results are supported by Multiwfn analysis on FMO composition of specific TSs, and MBO value of vital bonding, breaking.