Palladium‐Catalysed Oxidative Decarboxylative Cross‐Coupling of Heteroarenes with CF₃‐Acrylic Acids

Abstract

Whereas decarboxylative cross‐coupling is becoming an important tool in organic synthesis, the metal‐catalysed decarboxylative/direct C−H alkenylation using acrylic acid derivatives has been scarcely studied in the literature. Herein, we reported the first decarboxylative/direct C−H trifluoromethylalkenylation of heteroarenes using various 3‐aryl‐2‐trifluoromethylacrylic acids as coupling partners. Due to the electronic and steric features of the trifluoromethyl moiety, the protodecarboxylated compound is produced in large quantity during the reaction compared to the desired product. Nevertheless, we succeeded, albeit in low to fair yields, in obtaining the functionalized heterocycles bearing the trifluoromethyl alkene moiety.

Recent advances in catalytic decarboxylative transformations of carboxylic acid groups attached to a non-aromatic sp2or sp carbon

“…Subsequently, Bouillon and Couve-Bonnaire et al reported a strategy that enabled the Pd-catalyzed oxidative cross-coupling reaction between heteroarenes and CF 3 -bearing acrylic acids 99B (Scheme 46). 61 However, the reaction gave modest to moderate yields of final products 154 and double bond isomerization took place giving E : Z ratios within the range of 92/8 to 100/0.…”