Redox Activity of Pyridine-Oxazoline Ligands in the Stabilization of Low-Valent Organonickel Radical Complexes
- 1 April 2021
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 143 (14), 5295-5300
- https://doi.org/10.1021/jacs.1c00440
Abstract
Low-valent organonickel radical complexes are common intermediates in cross-coupling reactions and metalloenzyme-mediated processes. The electronic structures of N-ligand supported nickel complexes appear to vary depending on the actor ligands and the coordination number. The reduction products of a series of divalent (pyrox)Ni complexes establish the redox activity of pyrox in stabilizing electron-rich Ni(II)–alkyl and −aryl complexes by adopting a ligand-centered radical configuration. The reduced pyrox imparts an enhanced trans-influence. In contrast, such redox activity was not observed in a (pyrox)Ni(I)–bromide species. The excellent capability of pyrox in stabilizing electron-rich Ni species resonates with its proclivity in promoting the reductive activation of C(sp3) electrophiles in cross-coupling reactions.Funding Information
- Alfred P. Sloan Foundation (FG-2018-10354)
- Camille and Henry Dreyfus Foundation (TC-19-019)
- National Institute of General Medical Sciences (R01GM127778)
This publication has 47 references indexed in Scilit:
- Mechanisms of Nickel-Catalyzed Coupling Reactions and Applications in Alkene FunctionalizationAccounts of Chemical Research, 2020
- Mechanisms of Nickel-Catalyzed Cross-Coupling ReactionsTrends in Chemistry, 2019
- Transition-Metal Catalysis of Nucleophilic Substitution Reactions: A Radical Alternative to SN1 and SN2 ProcessesACS Central Science, 2017
- Recent advances in homogeneous nickel catalysisNature, 2014
- Nickel-catalyzed cross coupling of non-activated alkyl halides: a mechanistic perspectiveChemical Science, 2011
- Nickel-Catalyzed Cross-Couplings Involving Carbon−Oxygen BondsChemical Reviews, 2010
- Diastereoselective Ni-Catalyzed Negishi Cross-Coupling Approach to Saturated, Fully OxygenatedC-Alkyl andC-Aryl GlycosidesJournal of the American Chemical Society, 2008
- Ligand Redox Effects in the Synthesis, Electronic Structure, and Reactivity of an Alkyl−Alkyl Cross-Coupling CatalystJournal of the American Chemical Society, 2006
- Evidence for a NiI Active Species in the Catalytic Cross-Coupling of Alkyl ElectrophilesJournal of the American Chemical Society, 2004
- Cross-Couplings of Unactivated Secondary Alkyl Halides: Room-Temperature Nickel-Catalyzed Negishi Reactions of Alkyl Bromides and IodidesJournal of the American Chemical Society, 2003