Copper-Catalyzed Aerobic Methyl/Methylene Oxygenation and C-H Formylation with a DABCO-DMSO System for the Synthesis of Carbonyl Indoles and Pyrroles

Copper-catalyzed aerobic methyl/methylene oxygenation of substituted indoles and pyrroles was developed using 1,4-diazabicyclo[2.2.2]octane (DABCO) as an additive in dimethyl sulfoxide (DMSO). Similar aerobic catalytic conditions could also be utilized for direct C-H formylation of C(3) on indoles and C(2) on pyrroles.