Synthesis of C-1 Deuterated 3-Formylindoles by Organophotoredox Catalyzed Direct Formylation of Indoles with Deuterated Glyoxylic Acid

Direct formylation of feedstock indoles with newly developed, cost-effective deuterated glyoxylic acid as formylation agent under visible light and air (O2) as terminal oxidant has been developed. An isatin byproduct produced from the corresponding indole reactant serves as a facilitator for the formylation process. The simple, mild, metal-and oxidant-free protocol enables the synthesis of structurally diverse C1-deuterated 3-formylindoles with broad functional group tolerance and late-stage functionalization at a high level of D-incorporation (95-99%).

Automated summary

A direct formylation method using cost-effective deuterated glyoxylic acid as the formylation agent has been developed. This method allows for the synthesis of structurally diverse C1-deuterated 3-formylindoles with high D-incorporation using visible light and air as the terminal oxidant.