Application Of (Diacetoxyiodo) Benzene In C-H Bond Functionalization

With the concept of green chemistry,convenient and uncomplicated C-H bond functionalization is more widely used by chemists in the synthesis.This C-H bond functionalization strategy avoids the pre-functionalization of the substrate,improves the efficiency of the atom econmy and plays an important role in organic synthesis.In recent years,our group are folused on the C-H bond functionalization by hypervalent iodine under metal-free conditions.This paper mainly focused on the application of(diacetoxyiodo)benzene in C-H bond functionalization,construction of C-hetero bond.The paper is divided into the following three aspects.In the first part,β-acetoxy alcohols can be synthesized in good yields with excellent diastereoselectivity from tertiary alcohols without directing groups through PhI(OAc)2-mediated metal-free condition.Mechanistic studies showed that theβ-acetoxylation process might undergo dehydration and sequential highly regioselective and diastereoseletive dioxygenation.The method was successfully applied to the modification of chiral camphor.The second part,diverse 2,3-disubstituted indoles could be synthesized efficiently in good yields via an iodine(Ⅲ)reagent Promoted intramolecular amination of 2-alkenylainilines.This process is controlled by sterically aryl moiety of iodobenzene diacetate,and 3,5-dimethyliodobenzene acetate provided the best yield.The reaction tolerates a variety of functional groups.The preparation of 3-methylindole and the synthesis of carbazolone have laid the foundation for the modification of more complex molecules.In the third part,we inverstigated the sp3 C-H functionalization of 2-(methyl(prop-2-yn-1-yl)amino)-N-phenylbenzamide methylene,to synthesize quinazolinone compounds.The reaction solvent,temperature,oxidant species and additives were studied in detail,and the temperature was the most powerful to improve the reaction yield.The structure containing the alkynyl moiety provides the possibility for the subsequent complex molecular skeleton modification.