Transition Metal-catalyzed C-H Activation Synthesis Of Heterocyclic Compounds

In the synthesis of organic and medicinal molecules,the C-H activation with the transition metal-catalyst has been increasingly mature.Because of the steps economic and atomic economic,C-H functionalization processes can significantly simplify the synthesis of pharmaceuticals,natural products,agrochemicals,polymers,and feedstock commodity chemicals.In this paper,we studied the application of C-H bond functionalization to synthesis of heterocyclic structures via cobalt and rhodium catalyst.The main contents include:1.Introduced the development status of heterocyclic compounds synthesised by C-H activation of cobalt catalysis.Simple introduced the Cp*Co(?)and the cheap cobalt catalyst,the research progress is classificated according to alkenes,alkynes,aromatic,allylation,carbonylation and cyano.2.Cheap Co(?)catalytic oxidation C-H activation cyclization.In this chapter,we report a traceless Cobalt-catalyzed bidentate C-H activation approach for in-situ synthesis of isoquinoline.There have a lot of methods to synthesis isoquinoline structure via C-H activation,but it was the first time which used cheap cobalt catalyst bidentate C-H activation,so it has a certain meaning in the field of C-H activation.The reaction has the following advantages:1)The first time to used that directing group.2)2-pyridine can be removed after cyclization.3)Use oxygen in the air as an oxidant.Furthermore,the mechanism of this reaction system was examined and the result shown that the C-H activation step was rate-determining in the catalytic process.3.Cp*Rh(?)catalyzes C-H activation cyclization.In this chapter,we report the discovery of N-tert-butyloxycarbonyl(N-Boc)cleavage to construct the nitrogen heterocyclic compound.Rh(?)-catalyzed coupling of N-Boc hydrazone with diazodiester provides efficient access to produced 2,3-Benzodiazepines,an important structural motif present in drug compounds,which can exhibit many important pharmacological and biological activities.For example,tofisopam is an anxiolytic agent in humans,nerisopam and girisopam proved to be biologically active.