Understanding Off-Cycle and Deactivation Pathways in Radical-Type Carbene Transfer Catalysis

Area of Science:

• Organometallic Chemistry
• Catalysis
• Organic Synthesis

Background:

• Transition metal radical-type carbene transfer catalysis offers sustainable and atom-efficient C-C bond formation.
• Significant research has advanced this methodology, yielding innovative synthetic routes and mechanistic insights.
• Carbene radical complexes exhibit complex reactivity, including off-cycle pathways.

Purpose of the Study:

• To demonstrate how understanding off-cycle and deactivation pathways can solve challenges.
• To reveal how studying these pathways can uncover novel reactivity for new applications.
• To stimulate further development of radical-type carbene transfer reactions.

Main Methods:

• Combined experimental and theoretical investigations.
• Elucidation of carbene radical complex reactivity.
• Analysis of off-cycle pathways and catalyst deactivation mechanisms.

Main Results:

• Off-cycle pathways can involve N-enolate and bridging carbene formation.
• Undesired hydrogen atom transfer from the reaction medium can deactivate catalysts.
• Understanding these pathways provides solutions to circumvent them.

Conclusions:

• Knowledge of off-cycle and deactivation pathways is crucial for optimizing carbene transfer catalysis.
• Studying these less-understood pathways can lead to the discovery of new catalytic applications.
• Further exploration of off-cycle species in metalloradical catalysis will drive innovation.