Upgrading ketone synthesis direct from carboxylic acids and organohalides

The ketone functional group has a unique reactivity in organic chemistry and is associated with a number of useful reactions. Catalytic methods for ketone synthesis are continually being developed. Here, we report a photoredox, nickel and phosphoranyl radical synergistic cross-electrophile coupling of commercially available chemicals, aromatic acids and aryl/alkyl bromides. This allows for concise synthesis of highly functionalized ketones directly, without the preparation of activated carbonyl intermediates or organometallic compounds, and thus complements the conventional Weinreb ketone synthesis. Use of the appropriate photocatalyst, ligand amount and solvents can match the reaction rate required by any simple catalytic cycle. The practicality and synthetic robustness of the reaction are illustrated by the facile synthesis of complex ketones from readily available feedstock chemicals.


General procedure for the reaction conditions
Ni precatalyst air-condition in fume hood

Control experiment with additives
In the nitrogen-filled glove box, an oven-dried vial (8 mL  demonstrates the generation of acyl radical during the reaction process.

Quantum yield measurement
The quantum yield (ф) was determined by the known ferrioxalate actinometry method.
A ferrioxalate actinometry solution was prepared by following the   In order to determine whether a radical-chain reaction is involved, the quantum yield measurement was conducted, and gives the quantum yield (Φ) of the photoreaction, 35%. Thus, a radical chain pathway is less likely.

Luminescence quenching experiment
The luminescence quenching experiment was taken using a Cary Eclipse fluorescence  Subsequently, the tube was evacuated and backfilled with Ar (three times