Abstract
Nickel-catalyzed cross-coupling and photoredox catalytic reactions has found widespread
utilities in organic synthesis. Redox processes are key intermediate steps in many
catalytic cycles. As a result, it is pertinent to measure and document the redox potentials
of various nickel species as precatalysts, catalysts, and intermediates. The redox
potentials of a transition-metal complex are governed by its oxidation state, ligand,
and the solvent environment. This article tabulates experimentally measured redox
potentials of nickel complexes supported on common ligands under various conditions.
This review article serves as a versatile tool to help synthetic organic and organometallic
chemists evaluate the feasibility and kinetics of redox events occurring at the nickel
center, when designing catalytic reactions and preparing nickel complexes.
1 Introduction
1.1 Scope
1.2 Measurement of Formal Redox Potentials
1.3 Redox Potentials in Nonaqueous Solution
2 Redox Potentials of Nickel Complexes
2.1 Redox Potentials of (Phosphine)Ni Complexes
2.2 Redox Potentials of (Nitrogen)Ni Complexes
2.3 Redox Potentials of (NHC)Ni Complexes
Key words
redox potentials - nickel - cyclic voltammetry - reduction - oxidation