Research On The Synthesis Of Compounds Containing Benzofuran And Indene Structures Based On Rhodium-catalyzed Activation Of CH Bonds

The structural units of benzofuran and indene are widely present in many drugs and natural products,and most of them have been showed excellent pharmacological and physiological activities.In recent decades,there have been many reports on the synthesis of benzofuran and indene structural units at home and abroad,but by consulting the literature we found that the synthesis of benzofuran and indene structural units has been rarely reported.We suspect that such unique structural units may have unique physiological activities,so the synthesis of such skeletons has certain research value.Among them,transition metal-catalyzed C-H functionalization using directing groups has attracted great attention.Among them,oxidizing directing groups have attracted our attention,because the catalysts can be recycled by using the oxidation of the directing groups,even if the additional oxidants aren't needed to add the reaction system,which meets the demands of green chemistry.Therefore,using the special properties of the oxidation-directing group to achieve successive C-H functionalization of the aromatic ring to synthesize structural units containing both benzofuran and indene has certain feasibility and important practical significance.The main contents of this paper include:A series of compounds containing both benzofuran and indene structural units were synthesized by using the commercialized[Cp^*RhCl₂]₂ as catalyst through successive C-H functionalization.The reaction conditions are simple and mild,and the substrates have good tolerance.It has moderate to excellent regioselectivity,can successfully achieve gram-scale reaction,and the product can be further derivatized.Finally,a simple exploration of the mechanism is proposed,and a reasonable mechanism is proposed.