Ligand-ligated Ni–Al bimetallic catalysis for C–H and C–C bond activation

Abstract

Compared with non-ligated Ni−Al bimetallic catalysis, bifunctional ligand-ligated Ni−Al bimetallic catalysis displays stronger synergism, not only affecting electronic property and steric hindrance of substrates, but also producing directing effect for...

Phosphine Oxide-Promoted Rh(I)-Catalyzed C–H Cyclization of Benzimidazoles with Alkenes

“…We recently explored a wide range of inert C–H and C–C bond activation reactions by using phosphine oxide-ligated Ni and Al bimetallic catalysis [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. However, the replacement of nickel with other transition metals has been faced with big challenges, probably owing to a mismatch between the two metals, or between metal catalysts and substrates.…”

Site‐Selective C−H Alkenylation of N‐Heteroarenes by Ligand‐Directed Co/Al and Co/Mg Cooperative Catalysis**

“…The cross‐coupling using secondary phosphine oxide (SPO) ligands, pioneered by Ackermann, [3] would also operate by similar bimetallic mechanism, especially when paired with Lewis acidic Grignard reagents [4, 5] . Ni/Al catalysts supported by (chiral) SPO ligands also represent highly effective TM/LA bimetallic systems for C−H activation of Lewis basic substrates, as pioneered by the groups of Cramer and Ye (Scheme 1b) [6, 7] . Thus, building on the seminal work of Nakao and Hiyama on Ni/Al catalysis, [8] SPO ligands have been designed to support, upon deprotonation and P V ‐to‐P III tautomerization, Ni 0 through the monodentate phosphorus and Al III through the anionic oxygen.…”

“…[4,5] Ni/Al catalysts supported by (chiral) SPO ligands also represent highly effective TM/LA bimetallic systems for CÀ H activation of Lewis basic substrates, as pioneered by the groups of Cramer and Ye (Scheme 1b). [6,7] Thus, building on the seminal work of Nakao and Hiyama on Ni/Al catalysis, [8] SPO ligands have been designed to support, upon deprotonation and P V -to-P III tautomerization, Ni 0 through the monodentate phosphorus and Al III through the anionic oxygen. Such bimetallic catalysts have been successful not only in the enantioselective CÀ H functionalization of substrates with single or enantiotopic CÀ H reaction site(s), [7a-c, 9, 10] but also in achieving site selectivity that is distinct from the inherent selectivity of the combination of separate Ni and Al catalysts.…”

Amplifying Reactivity of Metal Hydrides: A Heterotrimetallic NiAl2(μ2-H)2 Catalyst for the Dearomatization of N-Heterocycles

“…In the interest of further exploring cooperative transformations in multimetallic assemblies, well-defined heterometallic species incorporating Earth-abundant metals have been of interest with several relevant examples reported in the past decade. − Nickel–alane complexes have been of particular interest given the wide breadth of catalytic ability by nickel and the successful use of aluminum additives as cocatalysts (Figure b). − However, Al is coordinatively saturated in most examples, rendering its primary role to modulating the electron density at the transition metal.…”