It was found that the conversion reaction between styrene and open chain ether

New progress has been made in the study of bifunctionalization of styrene

Research background and history

Styrene is a bulk chemical product, and the study of one-step bifunctionalization of styrene is of great value. Wang Naixing, a researcher at the Institute of Physics and Chemistry Technology of the Chinese Academy of Sciences, has been exploring since 2012 and has achieved high-value conversion of styrene to aliphatic alcohols, ketones, and nitriles. Several articles have been published in the organic chemistry journal Org. Lett.

Latest research results

The research group recently discovered that styrene and open-chain ethers can achieve high-value conversions to form bifunctional drug intermediates.

Research methods and mechanisms

In this study, all 18 reaction products were characterized by hydrogen NMR, carbon spectroscopy and high-resolution mass spectrometry. On the reverse side of the mechanism study, the reaction was inhibited by free radical trapping agents TEMPO and BHT, respectively. The results showed that the addition of free radical trapping agents tended to quench the reaction, indicating that the reaction belonged to the free radical process.

They also determined the dominant check point of the reaction by means of density functional theory calculations, supporting the proposed free radical mechanism.

Hydrogen NMR Spectroscopy Characteristic Analysis

They also found that in the hydrogen NMR spectra of the obtained compounds, under the influence of the chiral center, the two hydrogen magnetism of the methylene at the α position are completely inequivalent, and some β-position protons of chiral carbon sometimes crack due to magnetic inequalities. One reason why individual β-position protons do not crack is that the conjugated electron circulation generated by the aromatic ring of the substituent weakens the magnetic inequalities of β-position protons; another reason is that the steric resistance effect of some longer hydrocarbon chains of the substituent weakens its magnetic inequalities.

Research results published

The research results were published in the journal Advanced Synthesis & Catalysis, 2019, 361, 1007-1011. The first author of the paper is Yan Zhan, a master's student jointly trained by Northwestern University and the Institute of Physics and Chemistry.