Study On The Coupling Reaction Of Diazophenyl Acetate And Carbonyl Compounds

Diazo compounds are amphiphilic reagents with high reactivity and wide application.With the rapid development of diazo compounds in the field of organic synthesis,they are easy to decompose into corresponding carbene or metal carbene sources under the conditions of light,heat or transition metal catalysis,and participate in a series of valuable synthetic transformations,including X-H/C-X（X=C,O,S,N,etc.）insertion,cycloaddition,yelide formation and other important reactions.At the same time,it also attracts more and more chemists to study the efficient application of more diazo compounds.This dissertation focuses on exploring the coupling rearrangement reactions of diazophenylacetate under different catalytic conditions,involving blue light-induced C-C bond insertion reaction between diazophenylacetate and 1,3-diketones.and copper-catalyzed rearrangement cyclization of diazophenyl acetate and2-aminochalcone.The specific research results are as follows:（1）The C-C bond insertion reaction of diazophenylacetate and 1,3-diketones induced by blue light was realized,and a series of products containing total carbon were obtained in medium yieldα-1,4-dicarbonyl products of quaternary centers.The reaction conditions were optimized by using ethyl 2-diazo-2-phenylacetate（3 equiv.）and dibenzoylmethane（1 equiv.）as starting materials,dichloromethane as solvent,under nitrogen atmosphere and blue light irradiation After the reaction was carried out at 40℃for 20 h,the yield of the target product 1,4-dicarbonyl compound was 78%.The only energy source involved in the conversion in this method is the blue LED light,and there is no need to add other chemical substances to catalyze the reaction,which is in line with the concept of sustainable development.（2）A copper catalyzed ester rearrangement[4+1]-cyclization reaction of diazophenylacetate and 2-aminochalcone compounds was developed.A series of indole heterocyclic products with medium to good yield can be obtained through the steps of carbene N-H bond insertion,intramolecular aldol condensation and 1,2-ester group migration.By exploring the effect of reaction conditions on the yield,it was finally determined that in the air atmosphere,the reaction substrates were 2-diazo-2-phenylacetate（2 equiv.）and 2-aminochalcone（1 equiv.）,and the metal catalysts were 10 mol%Cu（OTf）₂,the solvent is DCE,react in a metal bath at 60°C for 12 h,and the yield of the target indole derivatives is 92%.The reaction has the characteristics of a wide range of substrates,and the experimental operation process is very simple.