Αποτελέσματα Αναζήτησης
Mechanisms of Nickel-Catalyzed Cross-Coupling Reactions. Highlights. The stability of open-shell Ni (I) and Ni (III) intermediates, in combination with the use of N-containing ligands, gives rise to Ni-mediated radical pathways that are prevalent in the cross-coupling of alkyl electrophiles.
2 Απρ 2020 · The tendency of Ni to undergo one-electron redox processes prompted us to explore dinuclear Ni-mediated bond formations. These studies provide insight into Ni–Ni bonding and how two metal centers react cooperatively to promote C–C, C–X, and N–N bond forming reductive elimination.
These steps resonate with mechanistic proposals in nickel-catalyzed cross-coupling, photoredox, and electrocatalytic reactions. Herein, we present our insights into each step involving radicals, including initiation, propagation, termination, and the nuances of kinetics, origins of selectivity, and ligand effects.
17 Φεβ 2015 · The prominent achievements of nickel catalysis include cyclizations, cycloaddition reactions, and multicomponent couplings. (25-27) In these transformations, nickel species demonstrated outstanding ability to coordinate and activate unsaturated organic molecules (alkenes, dienes, alkynes, etc.).
4 Απρ 2020 · Preliminary mechanistic observations reveal the formation of benzylic radicals as intermediates (Scheme 5). A plausible mechanism begins with a Ni(I)–Ph-mediated migratory insertion (step iii), followed by oxidative addition to activate another molecule of PhBr (step iv).
14 Μαΐ 2014 · Tremendous advances have been made in nickel catalysis over the past decade. Several key properties of nickel, such as facile oxidative addition and ready access to multiple oxidation states,...
21 Απρ 2020 · Nickel complexes exhibit distinct properties from other group 10 metals, including a small nuclear radius, high paring energy, low electronegativity, and low redox potentials. These properties enable Ni catalysts to accommodate and stabilize paramagnetic intermediates, access radical pathways, and u ….
