Cobalt-Catalyzed Enantioconvergent Hydrogenation of Minimally Functionalized Isomeric Olefins

Abstract

Investigation on asymmetric hydrogenation of olefins is of great importance in both pharmaceutical molecule synthesis and chemical industry due to the high demand for enantiopure compounds. The established methods often require geometrically pure olefins. The enantioconvergent reaction provided the possibility to access a single stereoisomer via hydrogenation of E/Z-olefin mixtures; however, a polar functional group next to the carbon–carbon double bond was usually necessary. Here, we reported a cobalt-catalyzed enantioconvergent hydrogenation of readily available minimally functionalized E/Z-olefin mixtures. This strategy shows good functional group tolerance and provides an alternative means to enantioconvergent transformation. The preliminary mechanistic studies indicated that cobalt-catalyzed isomerization was the key to achieve the convergent transformation.

Cobalt‐Catalyzed Asymmetric Hydrogenation: Substrate Specificity and Mechanistic Variability

“…Co/OIP catalyzed enantioconvergent hydrogenation of isomeric olefins. [33] Substrate scope (top) and proposed mechanism (bottom). and redox neutral pathway in Co-catalyzed asymmetric olefin hydrogenation.…”

Earth-Abundant Transition Metal Catalyzed Asymmetric Hydrogenation of Minimally Functionalized Alkenes

“…In 2022, our group 44 used imidazoline iminopyridine (IIP) ligand supported cobalt complex Co-12 to achieve the enantioconvergent hydrogenation of E / Z -isomers with high enantioselectivity for the first time (Scheme 6 ). The cobalt catalyst could coordinate with more hindered trisubstituted alkenes by introducing a ligand framework modified by a formyl imine group with lower steric hindrance.…”

Concise synthesis of Azilect via cobalt-catalyzed enantioselective hydrogenation in a bio-based solvent

“…After the discovery of cobalt catalyzed asymmetric hydrogenation of functionalized olefins 33 via high throughput screening, first row transition metals 34 in asymmetric hydrogenation 35 have become an attractive and important area of research, especially Co-catalyzed enantioselective olefin hydrogenation. The use of readily available cobalt precursors and enantiopure ligands have generated highly active catalysts for the synthesis of levetiracetam, 36 hydrogenation of N-functionalized imines, 37 α,β-unsaturated carboxylic acids, [38][39][40] E/Z alkenes, 41 functionalized alkynes, 42,43 enynes, 44 minimally functionalized alkenes, [45][46][47][48] azole derived tri-substituted alkene, 49 and other unsaturated compounds. 13,34,[50][51][52][53] A handful of Rh-based homogeneous catalysts are known for the preparation of chiral N-(indan-1yl)-acetamide (1b) [54][55][56][57] or, 1-indanamine (1c).…”