Advances in Ni^I/Ni^III-Catalyzed C(sp²)-Heteroatom Cross-Couplings

Area of Science:

• Organometallic Chemistry
• Catalysis
• Synthetic Organic Chemistry

Background:

• Nickel catalysis is an emerging alternative to palladium for C-(sp2)-heteroatom couplings.
• Current Ni(I)/Ni(III) systems face limitations including low activity and catalyst deactivation.
• Existing methods often require activated substrates and high catalyst loadings.

Purpose of the Study:

• To review recent advancements in Ni(I)/Ni(III) catalyzed C-(sp2)-heteroatom couplings.
• To address challenges hindering the practical application of nickel catalysis.
• To highlight strategies for improving catalyst efficiency and substrate scope.

Main Methods:

• Survey of strategies for generating active Ni(I) species from Ni(II) precatalysts.
• Discussion of mechanistic studies on deactivation pathways and oxidative addition.
• Review of novel synthetic methodologies and reaction conditions.

Main Results:

• Streamlined generation of catalytically competent Ni(I) species.
• Mechanistic insights into catalyst deactivation and rate-limiting steps.
• Demonstration of successful couplings using elevated temperatures, alternative electrophiles, additives, and tailored ligand fields.

Conclusions:

• Recent advances have overcome key limitations in Ni(I)/Ni(III) catalysis.
• Strategies discussed enable more efficient and broader applications of nickel-catalyzed couplings.
• The field is moving towards practical and robust catalytic systems.