Synthesis of isoquinolin-1,4-diones <i>via</i> photocatalytic C(sp ² )–C(sp ³ )-scission/oxidation of 4-(hydroxy(aryl)methyl)-isoquinolin-1(2 <i>H</i> )-ones

Dihydroisoquinolin-1,4-diones represent an important class of nitrogen-containing fused heterocyclic units. Their straightforward synthesis from readily available precursors would be attractive. Herein, we present a novel photocatalytic method enabling the direct synthesis of diverse 3-methoxy-2,3-dihydroisoquinoline-1,4-diones from 4-(hydroxy(aryl)methyl)-isoquinolin-1(2<i>H</i>)-ones. The method demonstrates high functional group tolerance, enabling further synthetic transformations for isoquinoline-1,4-diones containing C3 quaternary carbon centers.