The conjugate addition reaction of carbon nucleophiles to electron-deficient olefins is one of the most reliable methods for selective C–C bond formation. However, the conjugate addition to the vinylogous electron-deficient dienes has been much less developed, as there is considerably more difficulty in controlling the regioselectivity of the addition to these extended conjugate systems due to the presence of three electrophilic sites, as well as the stereoselectivity. Although still underdeveloped, new approaches to tackle these challenges are beginning to emerge. Both transition-metal-catalyzed and organocatalytic approaches are currently being developed to cope with the main selectivity issues of this type of process: regioselectivity (1,2-, 1,4-, and 1,6-addition) and stereoselectivity (asymmetric formation of the new C–C bonds). In this tutorial review, we have surveyed representative examples to get an overview of the recent advances obtained in the scope of the conjugate addition reaction of carbon nucleophiles to electron-deficient dienes.

Transition-metal-free C–C bond forming reactions of boronic acids are new emerging tools in organic synthesis which complement metal-based procedures.

This review summarizes the background and the state of the art of the coupling of the enolates of ketones and carboxylic acid derivatives, focusing on the stereoselectivity of the process. Compared with other synthetic applications of enolates, the stereoselective coupling of these species has been considered less in the literature. Recent developments making use of chiral auxiliaries have put forward the versatility of this procedure for the asymmetric synthesis of 1,4-dicarbonyl compounds.