Co(III)-catalyzed alkenylation of 2-pyridones by using terminal alkyne as a reaction partner with high regioselectivity has been demonstrated for the first time. The reaction conditions are mild and compatible with a wide range of substrate combinations. It also shows good functional group tolerance. It proceeds through cyclometalation followed by alkyne insertion and protodemetalation steps. The formation of fiveand seven-membered cobaltacycle intermediates was also detected through highresolution mass spectrometry.

This review focuses on providing comprehensive highlights of the recent advances in the field of cobalt-catalysed C−H functionalization and related synthetic concepts relying on these through oxygen atom coordination. In...

Strain-driven palladium/N-heterocyclic carbene-catalyzed C–C bond activation of diphenylcyclopropenone (DPC) has been explored for one-step access to trisubstituted α,β-unsaturated esters and amides. The designed transformation works under mild conditions providing exclusively a single stereoisomer. Mechanistic studies support the oxidative addition of the C–C bond of cyclopropenone to in-situ-generated Pd(0) intermediate. We have proved that vinylic hydrogen in the product is coming from phenol/aniline through deuterium-labeling studies. Late-stage functionalization of bioactive molecules such as procaine, estrone, and hymecromone demonstrates the robustness of this protocol.

In recent years, transition metal-catalyzed strong C–C bond activation has significantly attracted the attention of synthetic chemists. This protocol enables simultaneous and direct functionalization of two different M–C bonds. Among different types of C–C bond activation strategies, strain-driven C–C bond activation has resulted in various otherwise difficult transformations. In this context, palladium catalyst has been extensively used and studied due to its robust reactivity and selectivity. Herein we have briefly discussed palladium-catalyzed C–C bond activation of three- and four-membered cycloalkane derivatives.