ChemInform Abstract: TBHP Mediated Oxidation of N‐2‐Alkynylphenyl α‐Amino Carbonyl Compounds to Oxalic Amides Using Visible Light Photoredox Catalysis and Their Application in the Synthesis of 2‐Aryl Indoles.

Abstract

A visible light promoted and TBHP mediated oxidative reaction of N-2-alkynylphenyl α-amino carbonyl compounds to N-2-alkynylphenyl oxalic amides was developed. In the presence of CuBr and photocatalyst Ru(bpy)3Cl2·6H2O, the reaction proceeded smoothly to afford the corresponding oxalic amides under the irradiation of a 26 W compact fluorescence bulb at room temperature. Furthermore, N-2-alkynylphenyl oxalic amides could be subsequently transferred to 2-aryl indoles without an additional deacylation step through a favored 5-endo-dig N-cyclization process using AgNO3 as catalyst.