Instead of destroying organic compounds, for the first time the photo-Fenton reaction was employed to construct them. Oxindole and spiro-oxindole scaffolds, which are frequently found in natural products, were selected as molecular targets. The development of a photochemical flow reactor employing the photo-Fenton reaction in formamide resulted in an excellent synthetic methodology for oxindoles. Non-anhydrous conditions are required, and readily available chemicals and mild conditions are employed. Also, novel synthetic approaches for new spiro compounds were efficiently developed using functionalized oxindoles as key intermediates.

The exploitation of microwave irradiation in radical reactions, in which formamide was used as both the solvent and reagent, enabled the development of an ultrafast methodology for amidation via carbamoyl radicals. The synthesis of novel functionalized isoquinoline-1,3-diones in only 10 s is described for the first time. A very efficient and environmentally benign methodology was developed. Mild conditions, very short reaction time, low energy consumption, high atom economy, use of an inexpensive and green catalyst, nonanhydrous conditions, high selectivity, and nontoxic solvents are some advantages of this method. The low value of the E factor (6.1) reflects the low waste generation, making this method very attractive for industrial applications.

No abstract