Chem
ReviewTransition-metal-catalyzed C–H allylation reactions
The bigger picture
The synthetic utility of the “allyl” unit is well understood and is often encountered in flavor and fragrance industries, pharmaceuticals, supra-molecular assemblies, and synthetic bioactive natural products. Incorporation of an allyl moiety into a complex organic framework enhances the utility of the overall synthetic application due to its late-stage nature. Direct C–H allylation assures selective productive formation by limiting extra steps and precluding the by-product formation. The asymmetric variant especially contributes toward the ligand and catalyst designs for asymmetric functionalization. Employing inexpensive base metals, activation of inert C–C bond of allyl synthon, selective remote functionalization, utilizing unusual allyl coupling partners, designing exciting ligands for asymmetric synthesis, etc., are some of the attractive outcomes from this domain. Owing to the versatility for further transformations, C–H allylation strategies have emerged as a promising synthetic transformation.