Palladium-Catalyzed Decarbonylative Cyanation of Carboxylic Acids with TMSCN

Abstract

The direct decarbonylative cyanation of benzoic acids with TMSCN was achieved through palladium catalysis. By this strategy, a wide range of nitriles including those with functional groups was synthesized in good to high yields. Moreover, this reaction applied to modifying bioactive molecules such as adapalene, probenecid, telmisartan, and 3-methylflavone-8-carboxylic acid. These results demonstrate that this new reaction has potential synthetic value in organic synthesis.

Decarbonylative Alkynylation of Aryl Anhydrides via Palladium Catalysis

“…The proposed mechanism for this palladium-catalyzed decarbonylative alkynylation of aryl anhydrides is shown in Scheme . First, palladium inserted into one of the (CO)–O bonds of aryl anhydrides, which involves a reversible C–O bond activation. − Oxidative addition is followed by decarbonylation. Next, alkyne replaces the carboxyl group by transmetallation, generating Ar–Pd–alkyne intermediate and carboxylate.…”

“…In recent years, decarbonylative cross-coupling of carboxylic acid derivatives has entered the arena of organic synthesis. − Compared with typical aryl halides or pseudohalides, carboxylic acid derivatives used in decarbonylative reactions have several major advantages, such as broad availability, bench-stability, nontoxicity, and orthogonal reactivity to aryl halides and pseudohalides . Therefore, decarbonylative alkynylation reactions involving carboxylic acid derivatives as electrophilic reagents has received much attention .…”

“…The synthesis of activated amides and esters requires converting carboxylic acids to acyl chlorides and then reacting acyl chlorides with amines and phenols to obtain the corresponding activated amide and ester substrates . To address this point, our group has developed decarbonylative cross-coupling reactions of carboxylic acids activated in situ, which can directly utilize carboxylic acids as substrates for various transformations . The key point of this approach is the implementation of sterically hindered alkyl anhydrides, which can activate the aryl carboxylic acid substrates to aryl alkyl anhydrides.…”

Dehydration of Amides by Redox‐Active Phenalenyl Based Mn‐Catalyst

“…Isolated yield was calculated with respect to the amide substrate. 4-Chlorobenzonitrile (3a): [51] White solid. Yield 96 %.…”

Palladium-catalysed deaminative/decarboxylative cross-coupling of organoammonium salts with carboxylic acids

“…We have a deep interest in the conversion and utilization of amines and carboxylic acids. 8,9 Here, we report a deaminative and decarboxylative cross-coupling of organoammonium salts with carboxylic acids. Using this strategy, polyfluoroaryl carboxylic acids, propiolic acids and α-cyano benzyl carboxylic acid were decarboxylatively benzylated readily and transformed into the corresponding benzylic products in good-to-excellent yields.…”