Carbon‒Carbon Bond Activation of Ketones

C−C bond activation methods have found increasing importance in complex-molecule synthesis. A number of different approaches for C−C bond activation of ketones have been developed. Complex bridged, fused, and spirocyclic ring systems have been constructed through activation of strained ketones. Synthetically useful transformations with less strained ketones have started to appear. C−C bond activation has emerged as an increasingly useful approach for constructing complex molecular scaffolds through unusual bond-disconnection strategies. As a common versatile functional group, ketones provide an excellent handle and platform for C−C bond activation reactions. Utilizing strain-release, carbon-monoxide-extrusion, and directing-group (DG) approaches, diverse transformations of various ketones have been developed in the past few decades through cleavage of their α C−C bonds. This review highlights the development of C−C bond-activation strategies for both strained and less strained ketones with a focus on transition-metal (TM)-catalyzed approaches. C−C bond activation has emerged as an increasingly useful approach for constructing complex molecular scaffolds through unusual bond-disconnection strategies. As a common versatile functional group, ketones provide an excellent handle and platform for C−C bond activation reactions. Utilizing strain-release, carbon-monoxide-extrusion, and directing-group (DG) approaches, diverse transformations of various ketones have been developed in the past few decades through cleavage of their α C−C bonds. This review highlights the development of C−C bond-activation strategies for both strained and less strained ketones with a focus on transition-metal (TM)-catalyzed approaches. an organic reaction of a carbonyl compound in which the two groups attached to the carbonyl connect to each other with the loss of CO. a substituent on a molecule that can coordinate to metals and direct the metal to the proximity of the reaction site. a process in which an anionic ligand and a neutral ligand in a metal complex combine to generate a new coordinated anionic ligand. a process in which a metal is inserted into a covalent bond and the oxidation state and coordination number of the metal are both increased by two. a type of ground-state destabilization in ring systems that arises from distorted bond angles (Baeyer strain), torsional eclipsing interactions (Pitzer strain), and interactions of substituents on nonadjacent atoms (transannular strain). a process in which a ligand is transferred from one metal center to another. a process in which a carbon substituent β to the metal center is cleaved to form a metal-alkyl or -aryl species and the corresponding unsaturated unit. a process in which a hydrogen atom β to the metal center is cleaved to form a metal hydride species and the corresponding unsaturated unit.