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DOI: 10.1055/sos-SD-208-00078

Hay, M. B.; Hicks, J. D.Science of Synthesis: Cross Coupling and Heck-Type Reactions, (20132130.

The palladium-catalyzed amination of alkenyl halides by primary aromatic amines is an efficient alternative to classical condensation methods for the construction of N-arylimines 40, especially when the condensation reaction involves a volatile carbonyl substrate.[‌78‌] A significant limitation of this method is the narrow scope of alkenyl halide starting materials that have been used for this transformation, as most examples are 2-halopropenes or (1-halovinyl)benzenes. The amination of alkenyl bromides is typically carried out at elevated temperatures in toluene in the presence of a palladium catalyst containing a bidentate ligand, such as BINAP[‌79‌] or 1,1′-bis(diphenylphosphino)ferrocene,[‌78‌] and sodium tert-butoxide[‌79‌] or cesium carbonate[‌78‌] as the base (Scheme 26). Alkenyl chloride electrophiles require catalysts containing more electron-rich ligands such as dialkyl(biaryl)phosphines.[‌80‌] Interestingly, competition experiments have demonstrated that amine alkenylations proceed preferably to arylations when alkenyl and aryl bromides are present.[‌79‌] This is attributed to the faster oxidative addition rate of alkenyl bromides relative to aryl bromides.[‌79‌]

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