Redox-neutral C-H cyanation of tetrahydroisoquinolines under photoredox catalysis

Redox-neutral cyanation of C-H bond adjacent to a nitrogen atom was achieved by using the combination of a photoredox catalyst and p-toluenesulfonyl cyanide. The reaction of tetrahydroisoquinolines proceeded smoothly, affording the corresponding cyanated products selectively in good to high yield. Although the reaction rate became slower in the case of the substrates having electron-withdrawing groups, high yields were achieved by elongating the reaction time. Although the yields were only moderate, the reaction conditions were also applicable to N,N-dialkylanilines. (C) 2018 Elsevier Ltd. All rights reserved.