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

摘要

7,7'-Bis(((dimethylamiiio)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((dimethylami-no)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 deg 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.