Acridine yellow G as a photo-induced electron transfer catalyzed radical [4 + 2] aza-Diels-Alder annulation of imines

Abstract

For the preparation of polyfunctionalized piperidine scaffolds, a radical tandem five-condensation domino Knoevenagel-intramolecular [4 + 2] aza-Diels-Alder imin-based reaction was used. Based on acridine yellow G (AYG) as a photo-induced electron transfer (PET) photocatalyst, employing visible light as a renewable source of energy. AYG that is photochemically catalyzed has good yields, as well as outstanding atom economy, and ease of operation. As a result, a diverse set of chemical and environmental parameters can be measured across time. The turnover number (TON) and turnover frequency (TOF) of polyfunctionalized piperidine scaffolds have been computed. Also, gram-scale cyclization can occur, suggesting that the process might find application in industry.