Photocatalytic Alkylation/Arylative Cyclization of <i>N</i>-Acrylamides of <i>N</i>-Heteroarenes and Arylamines with Dihydroquinazolinones from Unactivated Ketones
Sandip Bag, Shubham Ojha, Sreelakshmi Venugopalan, Basudev Sahoo
Abstract
We describe a visible-light photoredox-catalyzed alkylation/arylative cyclization of N -acrylamides─from 2-arylindoles, 2-arylbenzimidazoles, or N -substituted anilines─with ketone-derived dihydroquinazolinones, accessing indolo- and benzimidazolo[2,1- a ]isoquinolines or 2-oxindoles. The consecutive incorporation of alkyl- and aryl-carbogenic motifs across a C=C bond via formal cleavage of ketone α-C–C and arene C–H bonds leads to the formation of five- and six-membered rings, with an all-carbon quaternary stereocenter. This dicarbofunctionalization elaborates aromatization-driven radical C–C functionalization of unactivated aliphatic ketones to construct diverse cyclic structures with functionality tolerance.