Pseudo‐Solid‐State Suzuki–Miyaura Reaction and the Role of Water Formed by Dehydration of Arylboronic Acids
Solvent-free reactions belong to a very attractive area of organic chemistry. The solvent-free Suzuki–Miyaura coupling is of special importance due to the problem of catalyst leaching in the presence of a solvent. This study investigates the course of reaction of solid aryl halides with arylboronic acids in the absence of a solvent and without any liquid additives. For the first time, a number of important conditions for performing a solid-state Suzuki–Miyaura reaction were analyzed in details. The results indicate a prominent role of water, which is formed as a by-product in the side reaction of arylboronic acid trimerization. Electron microscopy study revealed surprising changes occurring within the reaction mixture during the reaction and indicated the formation of spherical nano-sized particles containing the reaction product. Catalyst recycling was easily performed in the developed system and the product was isolated by sublimation, thus providing a possibility to completely avoid the use of solvents at all stages.
Reference: Eur. J. Org. Chem., 2019, 2019, 4239-4247
On-line version: https://onlinelibrary.wiley.com/doi/full/10.1002/e...
