No abstract

Direct C3-H acylation of quinoxalin-2(1H)-ones with α-oxocarboxylic acids under thermo conditions promoted by PIDA has been achieved in moderate to good yield. Mechanistic study revealed that the reaction proceeds via...

With aldehydes as the radical precursors under visible-light irradiation, a simple and mild PIFA-mediated C–H acylation reaction of quinoxalin-2(1H)-ones has been achieved.

The combination of the radical chemistry of ligand-to-metal charge transfer with metal catalysis by a single iron salt helps to realize the visible-light-promoted N–H alkylation of amides and N-heterocycles. A wide variety of amides and nitrogen-containing heterocycles were tolerated in our protocol to give N-alkylated products. The applicability of this protocol was further demonstrated by late-stage alkylation of N–H-containing pharmaceuticals. Moreover, N–H-alkylated α-amino tetrahydrofurans could be transformed into versatile ring-opened amino alcohols under reducing conditions. A mechanistic study revealed that hydrogen atom transfer by a tert-butoxyl radical and a chlorine radical was responsible for the activation of C­(sp3)–H precursors.

The metal‐free selective and diverse synthesis of three distinct sets of isoindolinones from 2‐alkynylbenzoic acids and amines has been achieved in a reaction‐condition‐controlled manner. This method exhibits valuable advantageous features such as available starting materials, broad substrate scope, excellent selectivity, good to high yields, good functional group tolerance, simple operation, high bond‐forming efficiency, and step economy, thus providing a convenient and efficient access to a variety of heterocyclic compounds incorporating the bioactive isoindolinone motif.