Rapid gas-liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide

Kyoko Mandai; Tetsuya Yamamoto; Hiroki Mandai; Aiichiro Nagaki

doi:10.3762/bjoc.18.67

Rapid gas-liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide

Beilstein J Org Chem. 2022 Jun 13:18:660-668. doi: 10.3762/bjoc.18.67. eCollection 2022.

Authors

Kyoko Mandai^{1

2}, Tetsuya Yamamoto¹, Hiroki Mandai², Aiichiro Nagaki¹

Affiliations

¹ Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-Ku, Kyoto, 615-8510, Japan.
² Department of Pharmaceutical Science, Faculty of Pharmaceutical Science, Gifu University of Medical Science, Nijigaoka, Kani-city, Gifu Prefecture, 509-0293, Japan.

Abstract

The enhanced reaction rate in the epoxidation of cyclohexene with air as an oxidant was discovered without any added catalyst utilizing a continuous flow reactor constructed with readily available stainless steel parts and devices. This continuous-flow process demonstrates a significant improvement in reaction time for highly selective epoxide production over the batch process due to the efficient mass transfer between the liquid phase and air. The flow process discovered was operated continuously with good operational stability, evaluated by a constant high yield of cyclohexene oxide, to obtain the desired product with high productivity.

Keywords: air; continuous flow; cyclohexene oxide; flow epoxidation; rapid gas–liquid reaction.

Grants and funding

This work was supported by JSPS KAKENHI (JP15H05849, JP17K06910, JP19K22186, JP20KK0121, JP21H01936, and JP21H05080), AMED (JP20ak0101090, JP21ak0101156, and JP22ama121042), CREST (JPMJCR18R1), JST A-step program (18067420), New Energy and Industrial Technology Development Organization (NEDO), the Japan Keirin Autorace Foundation, and the Ogasawara Foundation.