Copper complexes catalytic decarboxylation

Decarbonylation decarboxylation. At 110-170° this complex in catalytic amounts effects decarbonylation of simple aldehydes in quantitative yield.2 Decarbonylation of typical indole-2-carboxaldehydes with in s/ta-generated catalyst proceeds in 82-95% yield. In fact, decarboxylation of some indole-2-carboxylic acids can be effected in higher overall yield by conversion to the aldehyde (LiAlH4 Mn02) followed by decarbonylation than by copper-catalyzed decarboxylation.3... 

The Cu(II) complex with polyaniline (emeraldine base) exhibits a higher catalytic efficiency for the dehydrogenative oxidation of cinnamyl alcohol into cin-namaldehyde. Iron(III) chloride is similarly used instead of copper(II) chloride. The catalytic system is applicable to the decarboxylative dehydrogenation of man-delic acid to give benzaldehyde. The cooperative catalysis of polyaniline and cop-per(II) chloride operates to form a reversible redox cycle under oxygen atmosphere as shown in Scheme 3.4. The copper salt contributes to not only oxidation process but also metallic doping. The reduced phenylenediamine anionic species appear to be stabilized by the metallic dopants. 

In 2010, Xue and coworkers [41] reported the viability of a copper-catalyzed decarboxylative coupling of alkynyl carboxylic acids with aryl h llides under relatively mild reaction conditions (Scheme 3.24a). On the basis of computation2il investigations, the authors proposed that in the initial step of the catalytic cycle, the copper(I) precursor was oxidized to a copper(lll) complex. 

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