Palladium-Catalyzed Methoxycarbonylation of 1,3-Butadiene to Methyl-3-Pentenoate: Introduction of a Continuous Process was written by Han, Li-Jun;Rao, Chong-Shun;Ma, Shuang-Shuang;Sheng, Gui-Yang;Zhang, Jun-Ping;Xu, Bao-Hua. And the article was included in Journal of Catalysis in 2021.Application In Synthesis of 4-Hexylpyridine This article mentions the following:
The base-assisted Pd(cod)Cl2/xantphos-catalyzed methoxycarbonylation of 1,3-butadiene (BD) to methyl-3-pentenoate (MP) was explored. Mechanistic studies suggested excessive xantphos (beyond an equimolar amount per Pd) as well as its substitute, pyridines of proper steric and electronic functionality, do participate catalytic cycle and significantly reduce activation energy by accelerating rate-limiting methanolysis step. As thus, all reaction parameters, especially solvents, were optimized based on Pd(cod)Cl2/Xantphos/4-hexylpyridine catalytic system, enabling construction of a continuous process. Systematic optimization demonstrated that a yield of 82% of MP with a purity of 99.8% could be reached under steady-state operation. In the experiment, the researchers used many compounds, for example, 4-Hexylpyridine (cas: 27876-24-0Application In Synthesis of 4-Hexylpyridine).
4-Hexylpyridine (cas: 27876-24-0) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Application In Synthesis of 4-Hexylpyridine