A Chemoselective and Scalable Transfer Hydrogenation of Aryl Imines by Rapid Continuous Flow Photoredox Catalysis
Rowan L Pilkington, Nikolai P Rossouw, Dean J van As, Anastasios Polyzos
CHIMIA International Journal for Chemistry | SWISS CHEMICAL SOC | Published : 2019
The chemoselective reduction of diaryl imines in the presence of competitively reducible groups is uniquely accessed through precise control of reaction and irradiation time by continuous flow visible light photoredox catalysis. The method enables the mild and efficient transfer hydrogenation of diaryl imines in the presence of sensitive functionality including halides, ester, ketone, and cyano groups. The flow protocol is efficient, rapid (>98% conversion within 9 min) and readily scaled to deliver multigram quantities of amine products in high purity.
The authors acknowledge Mr Vir H. Ghandi who assisted RLP with the experimental procedures and Professor Paul Francis (Deakin University) for the kind loan of the Syrris Asia syringe pump system. DvA acknowledges the University of Melbourne, Melbourne Research Scholarship (MRS). AP acknowledges the University of Melbourne and CSIRO for the joint Establishment Grant.