Researchers overcome challenge of using gold to do cross-coupling

Researchers in Professor Joseph Topczewski's lab have overcome a longstanding challenge of using gold as a redox active metal to do cross-coupling. To overcome traditional limitations, they used decarboxylation as the key step instead of transmetalation. This reaction has a broader scope than their prior work with palladium. An article on this research was published in the Journal of the American Chemical Society. "Gold Catalyzed Decarboxylative Cross-Coupling of Iodoarenes," was written by Ryan Daley, first author, Aaron Morrenzin, Sharon Neufeldt, and Professor Topczewski.

The research is an advance on cross-coupling, which is an incredibly important reaction. This reaction uses a gold catalyst unlike most couplings that use a palladium catalysts. By switching from palladium to gold, the decarboxylaiton step works much better. But, gold has a really hard time doing some of the other redox steps. This paper shows that these redox steps are viable at gold and can be used in cross-coupling. 

As part of Professor Topczewski's National Science Foundation CAREER Award, this research involves replacing traditional starting materials with readily available, lower energy, safer, and less toxic carboxylic acids. Professor Topczewski and his students are developing new synthetic methods for the decarboxylative cross-coupling and functionalization of (hetero)aryl carboxylic acids. This research focuses on the mechanistic elucidation of the reaction cycle, optimization of the ligand and metal complexes, expansion of the substrate scope, and the development of a broader array of functionalization reactions. Several metal complexes and mechanisms of decarboxylative coupling are being investigated.

Ryan, a Doctoral Dissertation Fellowship recipient, is focusing his research on overcoming the current limitations of decarboxylative cross-coupling methods. His dissertation focuses on developing palladium and gold catalyzed cross-couplings and improving the mechanistic understanding of these reactions.