Photochemical Alkylation of Heterocycles Enabled by Oxalic Dianion as Traceless Electron Donor

Herein, a catalyst- and metal-free strategy for the alkylation of various heterocycles was developed from readily available alkyl amines or carboxylic acids. Oxalic acid was the only inexpensive and commercially available reagent to realize the transformation under blue light irradiation at ambient temperature. The EDA complex formed between the Katritzky salt and oxalic dianion was the key to initiate the single electron transfer and generate the reactive alkyl radical to accomplish the alkylation with protonated nitrogen-containing heterocycles.