Visible Light-Mediated Metal-Free Decarboxylative Deuteration of Carboxylic Acid

Abstract

A metal-free visible light-induced decarboxylation of phenylacetic acid derivatives has been successfully developed. Without the additives, direct decarboxylative monodeuteration of acids was successfully achieved using cheap deuterium sources. Besides, in presence of air, similar catalytic systems provided ketone products.

Rhodium-catalysed decarbonylative C(sp2)–H alkylation of indolines with alkyl carboxylic acids and carboxylic anhydrides under redox-neutral conditions

“…Based on the aforementioned experimental results and previous reports, 13,14,16 we propose the reaction mechanism depicted in Fig. 1.…”

“…Alkyl carboxylic acids have recently garnered significant attention as an alkylating reagent owing to their advantages, such as being inexpensive, abundant in nature, stable under benchtop conditions and easy to handle. 13,14 Despite these advantages, only one precedent of C-7 alkylation of indolines has been reported to date: the palladium-catalysed oxidative decarboxylative alkylation of indolines with alkyl carboxylic acids (Scheme 1b). 15 In this method, primary alkyl carboxylic acids could not be coupled with indolines because of the low stability of the primary alkyl radical species.…”

“…Inspired by previous work on decarbonylative alkylation, 13 we began our investigation by employing 1-(pyrimidin-2-yl)indoline ( 1a ), propionic acid ( 2a ) and pivalic anhydride with various rhodium salts as a catalyst (Table 1). An initial experiment was performed in 1,4-dioxane at 130 °C for 18 h in the presence of [RhCl(CO) 2 ] 2 (2.5 mol%), producing the desired 7-ethyl-1-(pyrimidin-2-yl)indoline ( 3a ) in good yield (entry 1).…”

Diversified access to di- and trisubstituted allenes via nickel-catalysed reactions of 1,3-enynes with alkyl N-hydroxyphthalimide esters

“…In addition to polar and radical pathways, a reductive radical-polar crossover process was employed by us as a useful complementary route for the synthesis of functionalized 1,2-allenyl ketones 10 enabled by photoredox 5 a or nickel catalysis. 5 b Due to the efficient SET reduction of propargyl radicals followed by the propargyl-allenyl carbanion isomerization process, the reductive RPC-based pathway could be a straightforward route to access d -substituted allenes 11 in the presence of deuterated methanol. However, the available radical precursors of the secondary and tertiary alkyl silicates are still limited (Scheme 2a).…”

Green light enhanced the photostability and catalytic performance of fatty acid photodecarboxylase

“…Additionally, the optical attenuation from emulsions and inhibition of impurities to Cv FAP in waste lipids will restrain the catalytic efficiency of Cv FAP. Further assessments of ROS concentration and radical trapping 28 on Cv FAP catalysis are warranted to gain insight into the catalytic mechanism.…”