Asymmetric intermolecular allylic C–H amination of alkenes with aliphatic amines

Aliphatic allylic amines are found in a great variety of complex and biorelevant molecules. The direct allylic C–H amination of alkenes serves as the most straightforward method toward these motifs. However, use of widely available internal alkenes with aliphatic amines in this transformation remains a synthetic challenge. In particular, palladium catalysis faces the twin challenges of inefficient coordination of Pd(II) to internal alkenes but excessively tight and therefore inhibitory coordination of Pd(II) by basic aliphatic amines. We report a general solution to these problems. The developed protocol, in contrast to a classical Pd(II/0) scenario, operates through a blue light–induced Pd(0/I/II) manifold with mild aryl bromide oxidant. This open-shell approach also enables enantio- and diastereoselective allylic C–H amination. Description Illuminating C–N bond formation Forming carbon–nitrogen (C–N) bonds is integral to pharmaceutical synthesis. Palladium (Pd) catalysis is an especially efficient means to this end, but alkyl amines can deactivate the catalyst by tight binding. Several recent approaches to circumventing this problem in allylic amination have focused on modifying either the amines or the Pd coordination environment. Cheung et al. report a distinct protocol that operates through photoinduced electron transfer to form versatile Pd(I) intermediates. This method is also compatible with more densely substituted carbon frameworks and can selectively produce just one of two mirror image products. —JSY Photoexcitation promotes palladium-catalyzed C–N bond formation between internal alkenes and aliphatic amines.