Study On The Ring-Opening Cyclization Reation 2-Biphenyl-Aryl Donor-Acceptor Cyclopropane Compounds Abstract

A unique intramolecular arylative ring opening of 2-biaryl substituted donor-acceptor cyclopropanes in the presence of triflic acid was found to furnish 9H-fluorenes and 9,10-duhydrophenanthrenes,respectively.The chemoselectivity could be achieved by alternation of the solvent,temperature and loading amount of triflic acid.Furthermore,the representative scaled up experiments were manipulated with good outcomes.Firstly,the traditional methods of donor-acceptor cyclopropane ring addition and open ring addition are introduced.Secondly,the methods of realizing 9H-fluorene and 9,10-dihydrophenanthrene derivatives are summarized.The most important is to study the open-cyclization reaction of donor-acceptor cyclopropane compounds,that is,the construction of 2-aryl donor-acceptor cyclopropane,the synthesis of 9H-fluorene and 9,10-dihydrophenanthrene and phenanthrene compounds can be obtained under the action of trifluoromethane.Chemoselectivity between both of the products is achieved by modification of the solvent,temperature and level of triflic acid.Representative large scale experiments were also carried out successfully with good outcomes.This paper not only summarizes the research ideas of the subject,and looks into the future;It also includes specific experimental principles,structural characterization of raw materials and products.