Logo: to the web site of Uppsala University

This thesis explores the synthesis and application of 2-(diphenylphosphino)benzoic acid as a ligand in palladium-catalyzed Heck reactions. The ligand was synthesized via a two-step process involving the preparation of methyl-2-(diphenylphosphino)benzoate, followed by hydrolysis to yield the final product. Structural and purity confirmation using NMR spectroscopy, LC-MS, and GC-MS validated the synthesis. The catalytic performance of 2-(diphenylphosphino)benzoic acid was evaluated alongside its methyl ester derivative in three Heck reaction variants: the Heck reaction (bromobenzene and butyl acrylate), the oxidative Heck reaction (phenylboronic acid and butyl acrylate), and the decarboxylative Heck reaction (2-methoxybenzoic acid and butyl acrylate). Both ligands facilitated the synthesis of butyl cinnamate in the Heck and oxidative Heck reactions, with 2-(diphenylphosphino)benzoic acid consistently demonstrating better selectivity and greater purity. This superior performance may be attributed to differences in electronic effects and coordination properties, particularly the electron-withdrawing and chelating nature of its carboxylic acid group. However, neither ligand succeeded in producing butyl 2-methoxycinnamate in the decarboxylative Heck reactions, suggesting the need for further optimization. These results highlight the potential of 2-(diphenylphosphino)benzoic acid as a promising ligand for further exploration in palladium-catalyzed cross-coupling reactions.