{"title":"Selective hydrogenation of guaiacol to 2-methoxycyclohexanone over supported Pd catalysts","authors":"Yota Taniwaki, Yoshinao Nakagawa, Mizuho Yabushita, Keiichi Tomishige","doi":"10.1039/d4gc03793f","DOIUrl":null,"url":null,"abstract":"Selective hydrogenation of guaiacol to 2-methoxycyclohexanone was investigated with various Pd catalysts. This reaction is much more difficult than the hydrogenation of phenol to cyclohexanone, namely in terms of the low reactivity of guaiacol and the reduced selectivity of 2-methoxycyclohexanone due to the demethoxylation reaction. Pd/TiO<small><sub>2</sub></small> catalysts were found to be superior to other supported Pd catalysts in terms of activity and selectivity to 2-methoxycyclohexanone. The Pd dispersion did not affect the selectivity of Pd/TiO<small><sub>2</sub></small> catalysts. Meanwhile, the increase of Pd dispersion decreased the turnover frequency, and the optimum Pd dispersion was about 25%. The presence of residual chloride ions had a negative effect on the selectivity to 2-methoxycyclohexanone. The optimal Pd/TiO<small><sub>2</sub></small> catalyst gave 65% yield of 2-methoxycyclohexanone. The catalyst was reusable after washing with toluene solvent to extract residual organic species from the catalyst surface. The catalyst was capable of hydrogenating various phenolic compounds, namely methoxyphenols, into the corresponding cyclohexanone derivatives.","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":null,"pages":null},"PeriodicalIF":9.3000,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Green Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d4gc03793f","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Selective hydrogenation of guaiacol to 2-methoxycyclohexanone was investigated with various Pd catalysts. This reaction is much more difficult than the hydrogenation of phenol to cyclohexanone, namely in terms of the low reactivity of guaiacol and the reduced selectivity of 2-methoxycyclohexanone due to the demethoxylation reaction. Pd/TiO2 catalysts were found to be superior to other supported Pd catalysts in terms of activity and selectivity to 2-methoxycyclohexanone. The Pd dispersion did not affect the selectivity of Pd/TiO2 catalysts. Meanwhile, the increase of Pd dispersion decreased the turnover frequency, and the optimum Pd dispersion was about 25%. The presence of residual chloride ions had a negative effect on the selectivity to 2-methoxycyclohexanone. The optimal Pd/TiO2 catalyst gave 65% yield of 2-methoxycyclohexanone. The catalyst was reusable after washing with toluene solvent to extract residual organic species from the catalyst surface. The catalyst was capable of hydrogenating various phenolic compounds, namely methoxyphenols, into the corresponding cyclohexanone derivatives.
期刊介绍:
Green Chemistry is a journal that provides a unique forum for the publication of innovative research on the development of alternative green and sustainable technologies. The scope of Green Chemistry is based on the definition proposed by Anastas and Warner (Green Chemistry: Theory and Practice, P T Anastas and J C Warner, Oxford University Press, Oxford, 1998), which defines green chemistry as the utilisation of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products. Green Chemistry aims to reduce the environmental impact of the chemical enterprise by developing a technology base that is inherently non-toxic to living things and the environment. The journal welcomes submissions on all aspects of research relating to this endeavor and publishes original and significant cutting-edge research that is likely to be of wide general appeal. For a work to be published, it must present a significant advance in green chemistry, including a comparison with existing methods and a demonstration of advantages over those methods.