Study On The Reaction Of Radical Cyclic Cyclization Of Heterocyclic Compounds With Cyano Groups

Nitrogen heterocyclic compound are essential at the basis of life.From our basic necessities of life to the technological progress are deeply affected by nitrogen heterocyclic compounds.They are widely found in natural products and drug molecules.Among them,nitrogen heterocyclic compounds having quinolines and quinazolinone skeletons are widely used in the fields of medicinal chemistry and materials science.In view of the importance of these compounds,their preparation has always been a hot topic in organic synthesis.In the development of organic synthesis for a long time,the use of transition metal catalysts for the synthesis of heterocyclic compounds as the dominant strategy.The introduction of metals has made the reaction more complex,the harsh conditions required for the reaction,and the difficulty of pre-functionalized substrates have greatly limited the development of such reactions.Therefore,it is still an important goal to develop a simpler and milder method without metal involvement in the construction of quinoline and quinazolinone nitrogen heterocyclic compounds.Free radical chemistry has been considered to be disorderly and difficult to control in the early stages of its development.Until the 1980s and 1990s,many studies on the construction of nitrogen heterocyclic compounds by free radical processes have been reported.The advantages of free-radical tandem reactions are particularly prominent in a variety of directionally synthesized radical reactions.Free radical tandem reactions do not require the isolation of intermediates to complete the construction of complex compounds,such as natural products.In addition,the mild reaction conditions,simple steps,green cleanliness,and atomic economy are among the reasons why everyone favors this strategy for building nitrogen heterocyclic compounds.Cyano is a highly toxic inorganic cyanide in inorganic materials,but it is widely used in organic chemistry because it is easily converted into other useful functional groups.The substrates of N-cyanoalkenes are very good precursors for the construction of compounds such as quinolines and quinazolinones.The introduction of heteroatoms by means of radical tandem cyclization,avoid the toxic reagent and the use of harsh reaction conditions.Previous applications have been reported for the use of metal catalysis or photocatalysis for the construction of nitrogen heterocyclic compounds based on radical tandem reactions of this type of substrate.Based on two cyano-containing olefinic substrates,this paper attempts to study the simpler and more efficient reaction mode without metal participation to synthesize various quinoline derivatives,including the following two parts:1.Metal-free sequential decarbonylative annulation of N-cyanamides for the construction of 2,3-dihydropyrrolo[2,1-b]quinazolin-9(1H)-onesA convenient metal-free sequential decarbonylative annulation of unactivated alkenes for the construction of quinazolinones and dihydroisoquinolinones has been developed.This strategy features the oxidative decarbonylation of various secondary and tertiary alkyl aldehyde with N-cyanamide alkenes for the cascade construction of C-C/C-N bonds2.Oxidative Cyclization of o-Cyanoarylacrylamides to Aminoquinolin-2(1H)-one via C-C Double-Bond CleavageA novel oxidative cyclization of o-cyanoarylacrylamides for the synthesis of 4-amino-1,3-dimethylqui-nolin-2(1H)-one was developed.The introduction of amino groups in a simple manner avoids the use of sodium azide reagents.The main advantages of the process are the use of a cheap and easily available materials,mild conditions,the method convenient,and the 4-aminoquinolone derivatives are greatly enriched.