Study On The Activation Of C-H And C-N Bonds Mediated By Radical Intermediate

In this thesis,A highly selective sp3 C-N activation of tertiary anilines modulated by steric and thermodynamic factors was achieved using the TBN/TEMPO catalyst system.Furthermore,a facile construction of quinoline-2-carboxylate esters through an aerobic oxidation of alkyl 4-anilinocrotonates induced by a radical cation salt.The details are listed below:(1)A highly selective sp3 C-N cleavage of tertiary anilines was achieved using the TBN/TEMPO catalyst system.When N,N-diaklylanilines(alkyl,benzyl)were employed,the N-CH3 bond was selectively cleaved via radical C-H activation.Moreover,when the allyl group was installed,totally reverse selectivity was observed.It is worth noting that the solvent effect is also crucial to obtain high reaction efficiency and selectivity.t-butyl nitrite as a stable,readily available and inexpensive catalyst can efficiently promote C-N activation under metal-free reaction conditions.Compared with the traditional methods,the reaction is superior in higher efficiency,greener catalyst system,simple operation,milder reaction conditions and wider substrate scope.(2)A facile construction of quinoline-2-carboxylate esters through an aerobic oxidation of alkyl 4-anilinocrotonates is described.In the presence of dioxygen,sp3 C-H bonds in 4-anilinocrotonates can easily be oxidized by using a catalytic amount of a radical cation salt,providing a radical intermediate.After further oxidation and domino cyclization,the desired quinoline derivatives were afforded in high yields.This reaction provides a new way to construct the pharmaceutically relevant quinoline skeleton,avoiding harsh reaction conditions and tedious starting material synthesis.