Palladium-Catalyzed Decarboxylative Cross-Coupling Reaction Between Heteroaromatic Carboxylic Acids and Aryl Halides

Abstract

A full overview of the decarboxylative cross-coupling reaction between heteroaromatic carboxylic acids and aryl halides is described. This transformation employs palladium catalysts with short reaction times providing facile synthesis of aryl-substituted heteroaromatics. The effect of each reaction parameter including solvent, base, and additive employed as well as the full substrate scope of this transformation are reported. Mechanistic evidence is also disclosed that sheds light on possible reaction pathways.

Methyl 2‐Furoate: An Alternative Reagent to Furan for Palladium‐Catalysed Direct Arylation

“…The arylation of 2‐furoic acid via palladium‐catalysed decarboxylative coupling might also be an alternative to the use of furan 10. Such couplings have already reported by Bilodeau, Forgione and co‐workers 10d. However, they obtained only 41 % yield for the coupling of 2‐furoic acid with bromobenzene.…”

“…Methyl 5‐(4‐Trifluoromethylphenyl)furan‐2‐carboxylate (5): 10d 1‐Bromo‐4‐(trifluoromethyl)benzene (0.225 g, 1 mmol) and methyl 2‐furoate (0.504, 4 mmol) afforded 5 (0.186 g) in 69 % yield.…”

Thiophenes, Thiophene 1,1-Dioxides, and Thiophene 1-Oxides (Update 2011)

“…More recently, several new approaches have been reported. [172] The extrusion of carbon dioxide is also the initiating step in decarboxylative cross-coupling reactions, [171,[173][174][175][176][177] and is thus preparatively valuable. 170 8 8C (Scheme 43).…”

Catalytic Syntheses of N‐Heterocyclic Ynones and Ynediones by In Situ Activation of Carboxylic Acids with Oxalyl Chloride

“…[14,15] Cross-couplings of carboxylic acids using an excess of anhydrides or carbonates for activation allow for the carbonyl group to be maintained but result in the formation of simple alkyl and aryl ketones. [16] At the same time, the activation of carboxylic acids with oxalyl chloride is a widespread, mild, and clean method for the preparation of acid chlorides, which produces only gaseous by-products (carbon monoxide, carbon dioxide, and hydrogen chloride).…”