A rhodium catalyzed direct regioselective oxidative annulation by double C-H activation is described to synthesize highly substituted quinolones from pyridones. The reaction proceeds at mild conditions with broad scope and wide functional group tolerance. These novel quinolones were explored to recognize nitroaromatic compounds.

An efficient Rh -catalyzed redox-neutral method for the direct C8-arylation of quinoline N-oxides using diazonaphthalen-2(1H)-one as coupling partner has been demonstrated. The developed method is simple, scalable and straightforward with a wide range of substrate scope. The applicative potential was extended with a late-stage functionalization and straightforward synthesis of 8-azaBINOL derivative. A plausible reaction pathway was proposed after carrying out preliminary control studies.

An inexpensive copper-catalyzed cascade regioselective alkylation, followed by cyclocondensation of quinoline N-oxides with α-diazo esters has been achieved successfully to provide heteroarene-containing conjugated π-systems. The developed method is simple, straightforward, and economical with a broad range of substrate scope. The dual role of copper catalyst in the C-H bond functionalization and in Lewis acid-promoted cyclization was explored.

A Rh(III)-catalyzed highly efficient C6-alkylation of 2-pyridones has been achieved successfully with α-diazo carbonyl compounds. The developed method is simple, mild, and highly regioselective with a broad range of substrate scope. The regioselectivity is guided by the pyridyl substituent attached to the nitrogen center of the pyridone ring. The directing group can be easily removed, and the only formed byproduct is nitrogen. Furthermore, other similar heterocyclic scaffolds can also be functionalized regioselectively under the developed conditions.

An efficient pot-economic ands tep-economic Rh III -catalyzed site-selective direct amination/annulation strategy was developed for the synthesis of benzophenanthroline derivatives using quinoline N-oxides and anthranils. The methodw as further extended to the synthesis of nitrogen-containing extended p-conjugated benzophenanthrolinone derivatives. Late-stage functionalizations of cinchonidine and cinchophen derivativesa nd synthesis of abioactive quinolino-indole werea chieved.In contemporary organics ynthesis, efficiency and environmental sustainability are the key factors. To address these issues, effective approaches like "step-economic" and "pot-economic" synthesis has emerged rapidlydue to its simplicity and applicability in minimizing waste and reactiont ime. [1] Amongn itrogen-containing polyaromatic hydrocarbons (PAHs), [1,10]phenanthroline and [1,10]phenanthrolin-one are frequentm otifs in many pharmaceuticals, naturalp roducts, organic materials, and ligandsf or catalysis (Figure 1). [2,3] In particular, these scaffolds are used as potential ligands in gold-catalyzed transformations.