| The frameworks of 2-substituted azoles are widely found in pharmaceuticals,organic dyes,and natural products.Over the past decades,developing efficient proesses for the preparation of azole derivatives has received significant attention.Among them,the metal-catalyzed intramolecular cyclization of thioformanilides or the cross-coupling of carboxylic acids or aldehydes with 2-aminophenol are traditional methods.Recently,the direct C-H bond activation of azoles has emerged as potentially a more efficient and convenient alternative for the straightforward synthesis of such compounds.Many elegant arylating reagents have been reported.Although the above-mentioned arylation regents have been made to construct 2-substituted azoles,the development of novel and simple arylation and alkylation regent still remains highly desirable.Nitriles are readily available and relatively inexpensive chemicals that have been widely used in organic synthesis.Herein,we report on the transition-metal-free arylation of azoles with nitriles under simple reaction conditions to afford important 2-substituted azoles derivatives.In this dissertation,construct of 2-arylbenzoxazoles and 2-methylazoles and transformation of aryl nitriles are reviewed.By summarizing the law,thesis research mainly obtained the following results:1.We report on the transition-metal-free arylation of benzoxazoles with aryl nitriles,a variety of functional groups were tolerated and heteroaryl nitriles were also suitable substrates.Preliminary mechanistic studies indicated a ring-opening mechanism.This protocol provides a novel strategy for the efficient synthesis of complex 2-arylbenzoxazoles derivatives.2.The methylation of azoles with acetonitrile was also achieved in a similar manner.The conditions are simple and well-operated.This protocol provides a novel strategy for the efficient synthesis of complex 2-methylazoles derivatives. |
