Harnessing Anionic Rearrangements on the Benzenoid Ring of Quinoline for the Synthesis of 6,6‘-Disubstituted 7,7‘-Dihydroxy-8,8‘-biquinolyls

7,7‘-Bis(((dimethylamino)carbonyl)oxy)-8,8‘-biquinolyl (5) was
prepared in 71% yield by regioselective directed ortho
metalation (DoM) of N,N-dimethyl O-quinol-7-yl carbamate
(2) with LDA followed by oxidation with anhydrous ferric
chloride. DoM of 5 with excess LDA induced double anionic
ortho-Fries rearrangement and gave 6,6‘-bis((dimethylamino)carbonyl)-7,7‘-dihydroxy-8,8‘-biquinolyl (8). Treatment of
N,N-diethyl O-(8-iodoquinol-7-yl) carbamate (16) with LDA
in THF solvent at −78 °C, followed by addition of anhydrous
ferric chloride, resulted in an efficient tandem halogen-dance
dimerization process which afforded 7,7‘-bis(((diethylamino)carbonyl)oxy)-6,6‘-diiodo-8,8‘-biquinolyl (17) directly in 54%
yield.