Synthesis of 1,2-disubstituted benzenes and biphenyls from phthalic acids through electroreduction followed by electrocyclic reaction with alkynes

Various substituted 1,2-dihydrophthalic acids were synthesized by electroreduction of phthalic acids in excellent yields. The electrocyclic reaction of 1,2- dihydrophthalic acids or the methyl ester with alkynes gave 1,2-disubstituted benzenes and biphenyls in good yields together with fumaric acid or methyl fumarate.