Facile Synthesis Of Azaarene-Substituted3-Hydroxy-2-Oxindoles Via Lewis/Bronsted Acid-Catalyzed Sp~3C-H Functionalization

3-substituted-3-hydroxy-2-oxindoles are widely present in a range of biologicallyactive natural products and pharmaceuticals.The significant biological applications ofthis framework evoked new methods to construct the diversity of the unit.Methodssuppied to access this unit mainly focus on the synthsis of aryl-or alkyl substitued3-hydroxy-2-oxindoles. To the best of our knowledge, there are no reported methodfor accessing the azaarene-substituted-3-hydroxy-2-oxindoles.Lewis acid-catalyzed sp³C-H functionalization of2-methylazaarenes have beenreported only in few examples. Bronsted acid-catalyzed sp³C-H functionalization of2-methylazaarenes has no examples reported yet. According to this, Lewis acid-andBronsted acid-catalyzed sp³C-H functionalization of2-methylazaarene are nowstudied in this thesis to access azaarene-substituted-3-hydroxy-2-oxindoles.The initial studies were conducted on the reaction of2,6-lutidine and1-methyindoline. Based on this, several other aspects of this reaserch are as follows:（1） Different catalysts, solvents, temperature, and reaction times are tested, andthen the optimal conditions of the two catalyzed system are determined.（2） Under the optimal conditions in hand, the scope of the transformation areexplored. Kinds of azaarene-substituted-3-hydroxy-2-oxindoles are synthetized.（3） The Mp, status, IR （KBr）, HRMS （ESI）,¹H NMR and¹³C NMR of theproducts are shown in the thesis.（4） The possible mechanism of Lewis-and Bronsted-catalyzed sp³C-Hfunctionalization to access azaarene-substituted-3-hydroxy-2-oxindoles are proposed.The reactions of Lewis-and Bronsted-catalyzed sp³C-H functionalization ofazaarene with isatins and other dicarbonyls can be carried out in one step, which makethe synthesis of3-hydroxy-2-oxindoles more efficient. The success of this reactionsshould broaden the synthetic utility of Lewis acid and Bronsted acid in organicsynthesis.