Aryl-Decarboxylation Reactions Catalyzed by Palladium: Scope and Mechanism

Abstract

Palladium-catalyzed cross-couplings and related reactions have enabled many transformations essential to the synthesis of pharmaceuticals, agrochemicals, and organic materials. A related family of reactions that have received less attention are decarboxylative functionalization reactions. These reactions replace the preformed organometallic precursor (e.g., boronic acid or organostannane) with inexpensive and readily available carboxylic acids for many palladium-catalyzed reactions. This review focuses on catalyzed reactions where the elementary decarboxylation step is thought to occur at a palladium center. This review does not include decarboxylative reactions where decarboxylation is thought to be facilitated by a second metal (copper or silver) and is specifically limited to (hetero)arenecarboxylic acids. This review includes a discussion of oxidative Heck reactions, protodecarboxylation reactions, and cross-coupling reactions among others.1 Introduction2 Oxidative Heck Reactions3 Protodecarboxylation Reactions4 Cross-Coupling Reactions5 Other Reactions6 Conclusion

Gold Catalyzed Decarboxylative Cross-Coupling of Iodoarenes

“…It is well recognized in the area of palladium, copper, and silver decarboxylative cross-coupling that substrates with polarizing ortho substituents are particularly reactive. [44][45][46][47][48] Hoover and co-workers correlated the field effect parameter (Fortho) to reactivity for silver mediated protodecarboxylation. 55 Here, products 3m -3v could be isolated in good to excellent yield and these results qualitatively correlate to the field effect parameter.…”

“…It is particularly exciting that substrates 3x and 3y can be (%) isolated in any yield given the scope limitations of other decarboxylative cross-coupling reactions. 43,48,56 Substrates with an ortho C-H bond did not afford product with palladium catalyzed reactions 42,43,56 and a chlorine substituent (3y) is not considered to be particularly polarizing. A substrate with an orthomethoxy was not activated enough to provide an acceptable yield (3z, Fortho = 0.29).…”

Organometallic Gas‐phase Ion Chemistry and Catalysis: Insights Into the Use of Metal Catalysts to Promote Selectivity in the Reactions of Carboxylic Acids and Their Derivatives

“…Indeed, the use of cuprates (Krause, 2002;Rappoport & Marek, 2009; in cross-coupling reactions with alkylhalides is a textbook reaction (McMurry, 2008). There has been considerable interest in developing decarboxylative versions of these catalytic reactions in which carboxylic acids are used as substrates Goossen, Zimmermann, & Knauber, 2010;Rodriguez & Goossen, 2011;Shang & Liu, 2011;Dzik, Lange, & Goossen, 2012;Goossen & Goossen, 2013;Miao & Ge, 2014;Li et al, 2016;Satoh & Miura, 2015;Patra & Maiti, 2017;Perry & Larrosa, 2017;Sandfort et al, 2017;Campeau & Hazari, 2019;Daley & Topczewski, 2020;Moon & Lundgren, 2020). The solution-phase equivalent of the metal-mediated decarboxylative conversion of a carboxylate to a dithiocarboxylate discussed above (Equations 9,32,and 33), however, appears to be unprecedented in the literature.…”

Fluoride Ion-Initiated Decarboxylation of Silyl Alkynoates to Alkynylsilanes

“…Decarboxylative transformations are recognized as useful reactions in organic synthesis, because carboxylic acids and their ester derivatives are readily available starting materials. 1 Among them, the class of decarboxylation reactions that connect two moieties in a molecule separated by a carboxyl group, such as the protodecarboxylation of carboxylic acids and decarboxylative allylic alkylation of β-keto allyl esters, are operationally advantageous: the only stoichiometric coproduct is carbon dioxide, which is nontoxic, nonflammable, and readily removable from the reaction medium. 2 …”