Photoredox‐Catalyzed Decarboxylative Oxidation of Arylacetic Acids

Abstract

A photoredox-catalyzed decarboxylative oxidation of arylacetic acids, which are privileged scaffolds in pharmaceuticals, is reported herein. The established method is operationally simple and a variety of substrates are applicable, providing rapid access to dehomologated bioisosteres of common pharmaceuticals.

Decarboxylative oxygenation of carboxylic acids with O2via a non-heme manganese catalyst

“…We envisioned that a Mn-peroxide intermediate may be formed by the reaction of [Mn(dtbpy) 2 (1a-H)(OTf )] with O 2 in the decarboxylative oxidation under blue light. 34,67 Thus, a mixture of [Mn(dtbpy) 2 (OTf ) 2 ] and 1r, which was expected to afford [Mn(dtbpy) 2 (1r-H)(OTf )], was followed by UV-Vis spectroscopy with or without blue light irradiation. As shown in Fig.…”

“…So far, there have been only three reports, demonstrating the reaction via photoredox catalysis using molecular oxygen (O 2 ) under mild conditions. Two of these require precious Ru or Ir photocatalysts, 34,35 while the third produces a mixture of alcohols and ketones/ aldehydes as the products (Scheme 1a). 36 Other methods have been reported; however, they make use of stoichiometric strong oxidants, e.g.…”

Recent Synthetic Applications of the Hypervalent Iodine(III) Reagents in Visible-Light-Induced Photoredox Catalysis

“…Itami and co-workers developed a mild method for the photoredox-catalyzed decarboxylation of arylacetic acids by HIR in air, thus leading to various aryl-aldehydes and ketones (Sakakibara et al, 2018a ) ( Figure 11A ). Photoredox catalyst, HIR, blue light irradiation, and O 2 are all critically important for this transformation.…”

Small peptide diversification through photoredox-catalyzed oxidative C-terminal modification

“…Changing the photocatalyst to Ru(bpy) 3 Cl 2 slightly increased the yield (entry 2). 31 Decreasing the amount of MeOH in the reaction mixture and increasing the concentration had a beneficial impact on the yield (entries 3 and 4). Full conversion was observed with either 5 or 2 equivalents of methanol (entries 5 and 6).…”