Studies Of The Synthesis Of Benzofuran Derivatives And Dihydrobenzofuran

This thesis consists of two parts: the first part is the synthesis of benzofurans based on copper catalyzed Sonogashira coupling reaction;the second part is the construction of dihydrobenzofurans based on palladium catalyzed oxidative coupling reaction of sp~2 and sp~3 C-H bonds.Benzofurans are heterocyclic aromatic organic compounds,which widely exists in natural products,bioactive compounds and pharmaceutical molecules,and are very important structural units.In the first part of this paper,we described a new method for the synthesis of benzofuran derivatives and obtained 24 kinds of 2-substituted benzo[b]furans/furo-pyridines with a yield of 75%-95%.The raw material was cheap and easy to obtain,the conditions were mild,and the substitution group tolerance was very good.Dihydrobenzofuran scaffolds play an important role in life science and material chemistry.In addition,the intramolecular oxidative crosscoupling reactions of sp~2 and sp~3 C-H bonds are a very challenging problem in the field of C-H bond activation.In response to this challenge,we take 2-methyl-2-phenoxypropionic acid as raw material,use carboxyl as weak guiding group,and realize the simultaneous activation of sp~2 and sp~3 C-H bonds through ligand regulation,so as to synthesize multipurpose dihydrobenzofuran derivatives.At present,we get the expected product with 20% yield.The reaction is still in further optimization and exploration.