Copper(ii)-photocatalyzed decarboxylative oxygenation of carboxylic acids

Abstract

Showcasing the concept of light-induced homo¬lysis for the generation of radicals, the CuII-photocatalyzed decarboxylative oxygenation of carboxylic acids with molecular oxygen as the terminal oxidant is described. Two CuII-carboxylate complexes...

Iron-catalyzed ring-opening of cyclic carboxylic acids enabled by photoinduced ligand-to-metal charge transfer

“…Unlike the ring-opening reaction mechanism which was described above, primary and secondary carboxylic acids underwent iron photoinduced oxidative decarboxylation to generate the corresponding aldehydes and ketones in excellent to moderate yields ( 4a–4i ). 18 Several biologically and medicinally relevant molecules, such as isoxepac ( 3c ), indomethacin ( 3d ), and Ioxoprofen ( 3e ), were all suitable for oxidative decarboxylation and gave products 4c–4e in good yields. As representatives of acyclic tertiary carboxylic acids, compounds 3j and 3k were further subjected to the reaction conditions, and it was found that acetophenone ( 4j ) and benzophenone ( 4k ) were obtained as major products.…”

Ligand‐to‐Metal Charge Transfer (LMCT) Photochemistry at 3d‐Metal Complexes: An Emerging Tool for Sustainable Organic Synthesis

“…In 2022 Reiser, Rehbein and Castellano reported the decarboxylative synthesis of ketones and aldehydes (Scheme 12). [92] In this catalytic method oxygen is used as terminal oxidant, which traps carbon radical intermediates and allows turnover via the formation of Cu‐alkylperoxo species. The substrates employed are mainly benzylic, although they report two examples of cyclic secondary alkyl showing that this protocol can be extended to this class of inactivated substrates.…”

Emergence of ligand-to-metal charge transfer in homogeneous photocatalysis and photosensitization

“…In a follow-up paper from the same group, Reiser and coworkers demonstrated a LMCT-triggered visible-light-induced decarboxylative oxygenation with 19 examples, including several with quantitative yields (Figure 8e). 82 They also studied the two possible Cu II intermediates, dinuclear paddle-wheel type Cu II -caboxylates and monodentate Cu II -carboxylates, in which they were able to conclude that the reactive intermediates for the photocatalytic decarboxylation are the monodentate Cu II -carboxylates.…”

“…Copyright 2020 the American Chemical Society 81. (e) Schematic of the LMCT-triggered visible-light-induced decarboxylative oxygenation 82.…”