Rhodium(?)-catalyzed Oxidative C-H Functionalization Of Azomethine Ylides And Oxidative Synthesis Of Pyrazoles

The metal-catalyzed C-H bond activation is an effective way to formation theC-C, C-O, C-N bond. This method has the advantages of simplicity, atom economy.Since2007, rhodium complexes as a new type of metal catalysts widely used inactivation of C-H bonds for the replacement of palladium complexes. In order to formof C-C, C-N and bonds,rhodium can catalyze the oxidative coupling of the C-H bondwith unsaturated molecules such as alkenes, alkynes and aldehydes, This has beenadvieved rapid developments in the field of basic research and organic synthesisbecause of low amount of catalyst, high stability, mild conditions and high selectivity.Chapter1: Rhodium-Catalyzed Oxidative C-H Activation.This chapter focuses on the progress in Rh-catalyzed C-H activation to generateC-E (E=C, O, N) bond. Direct and chelated Rh catalyzed C-H bond activationreactions were introduced. The applications about these compounds in organicsynthesis were also described.Chapter2: Rhodium(?)-Catalyzed Oxidative C-H Functionalization ofAzomethine Ylides.A rhodium(?) complex can catalyze the oxidative coupling of azomethineimines with olefins, leading to the synthesis of1,2-dihydrophthalazines, olefinatedaldehydes, or fused pyridines, depending on the conditions used.Chapter3: Rh(?)-catalyzed oxidative synthesis of pyrazoles from azomethinesand acrylamides.A cationic Rh(?) complex has been developed to catalyze the oxidativecoupling of azomethine imines to acrylamides, to give trisubstituted pyrazoles inmoderate yield. In this process, the olefinic C-H bond of the acrylamide undergoesC-H activation, and the reaction subsequently proceeds via a different selectivity tothat reported for the coupling of acrylate esters.