Electro-Triggered Cascade Cyclization to Access Phosphinyl- Substituted N-Containing Heterocycles

An electro-triggered cascade cyclization strategy was disclosed with concomitant phosphinylation and N-heterocycle construction. It provides a novel and environmentally friendly approach to access phosphinyl-substituted N-heterocycles with no external metal catalyst, oxidant, or heating. Mechanistic studies have revealed that anodic oxidation of H-phosphorus compounds occurs first to generate the key P centered radical directly and cathodic reduction leads to the concurrent release of molecular hydrogen or methane. This protocol features simple operation, broad substrate scope, clean and mild conditions, and atom and step economy to form heterocycle-containing organophosphorus scaffolds.

Automated summary

An electro-triggered cascade cyclization strategy is presented for the synthesis of phosphinyl-substituted N-heterocycles. This environmentally friendly method does not require external metal catalyst, oxidant, or heating. Mechanistic studies show that anodic oxidation of H-phosphorus compounds generates the key P centered radical, while cathodic reduction simultaneously releases molecular hydrogen or methane. This protocol offers simple operation, broad substrate scope, clean and mild conditions, and atom and step economy for the formation of heterocycle-containing organophosphorus scaffolds.