Conjugated 1,3-dienes are a particularly versatile platform in the context of selective functionalization, and have been widely used as building blocks for organic synthesis. However, selective functionalization of 1,3-dienes is particularly challenging due to the numerous coordination and insertion modes conceivable for a transition metal catalyst.^[1] In recent years, efforts toward the development of selective catalytic transformations have been mainly focused on linear 1,3-dienes,^[2] while the limited synthetic availability of branched 1,3-dienes has severely hampered their use in the development of selective transformations.^[3] Within this context, our laboratory recently reported a general Ni-catalyzed protocol which streamlines access to 2‑substituted 1,3-dienes from readily available materials.^[4]

Herein we describe our results in the selective nickel-catalyzed hydrofunctionalization of this underexplored class of conjugated olefins. Using a (P,P) chiral ligand, 2-substituted 1,3-dienes could be hydroaminated by primary amines. High yields, regioselectivities and enantiomeric excesses were obtained for a wide variety of substrates.^[5] A mechanistic study combining kinetic analysis, stoechiometric experiments and supporting organometallic chemistry allowed us to gain in-depth understanding of the subtleties of this reaction, thus paving the way for its extension to other classes of substrates. Overall, we will disclose a catalytic strategy that solves critical challenges arising from the use of conjugated dienes, both in terms of reactivity (mono- vs. di-functionalization, parasitic reduction, competing isomerization) and selectivity (chemoselectivity, regioselectivity, enantioselectivity).

[1] Jessada Mahatthananchai, Aaron M. Dumas, Jeffrey W. Bode Angew. Chem., Int. Ed. 2012, 51, 10954.
[2] Vaneet Saini, Mark O’Dair, Matthew S. Sigman, J. Am. Chem. Soc. 2015, 137, 608.
[3] Khoa D. Nguyen, Daniel Herkommer, Michael J. Krische, J. Am. Chem. Soc. 2016, 138, 14210.
[4] Danielle Fiorito, Sarah Folliet, Yangbin Liu, Clément Mazet, ACS Catal. 2018, 8, 1392.
[5] Gaël Tran, Wen Shao, Clément Mazet, Manuscript in preparation