Hydroaminoalkyl Functionalization of Pyrimidin‐2(1H)‐ones by Visible Light Organophotocatalysis: A Radical Approach to Biginelli‐Type Dihydropyrimidines

Abstract

AbstractHerein, we report a visible‐light‐mediated hydroaminoalkylation of pyrimidin‐2(1H)‐ones via the aza‐Giese‐type reaction in presence of acridinium dye as photocatalyst under mild aerobic conditions. Using N‐Boc protected aminoalkyl trifluoroborates as radical precursors and various pyrimidine‐2(1H)‐one substrates, a diverse set of Biginelli‐type 3,4‐dihydropyrimidin‐2(1H)‐ones was prepared in 31–73% yields. Further transformation of the products obtained enabled the synthesis of 3,6,7,7a‐tetrahydro‐1H‐pyrrolo[3,4‐d]pyrimidine‐2,5‐dione derivatives which showed promise as inhibitors of poly (ADP‐ribose) polymerase (PARP) enzymes (IC50 0.46–1.12 μM for PARP‐2 in a fluorometric assay).