{"title":"Rapid and Metal-Free Green Synthesis of Coumarins Catalyzed by Humic Acid","authors":"Ling Wei, Yichun Wang, Qixuan Huang, Hongshe Wang","doi":"10.2174/0115701786318539240822112936","DOIUrl":null,"url":null,"abstract":": In recent years, numerous methods have been developed for the synthesis of coumarins via Pechmann reaction catalyzed by various catalysts. Although each of the synthetic strategies previously reported has its own merit, most of these methods are associated with certain disadvantages, including the use of commercially unavailable metal catalysts and organic solvents, low yields, and long reaction times. Therefore, the development of a highly efficient, green, and sustainable catalytic methodology for the synthesis of coumarins is still desirable. Humic acid has been found to be an efficient catalyst for the synthesis of coumarins via the Pechmann reaction at 80oC under solvent-free conditions. The methodology enables the synthesis of structurally diverse coumarins from phenols and β-keto esters within 5-8 min in high yields (91-99%). The green, commercially available, inexpensive organocatalyst can be effectively recycled and reused five times with no significant dropdown in the yield of the product. The method reported has the advantages of high yield, no need for metal catalysts, short reaction time, simple operation, and green and reusable catalyst.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7000,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Letters in Organic Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.2174/0115701786318539240822112936","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
引用次数: 0
Abstract
: In recent years, numerous methods have been developed for the synthesis of coumarins via Pechmann reaction catalyzed by various catalysts. Although each of the synthetic strategies previously reported has its own merit, most of these methods are associated with certain disadvantages, including the use of commercially unavailable metal catalysts and organic solvents, low yields, and long reaction times. Therefore, the development of a highly efficient, green, and sustainable catalytic methodology for the synthesis of coumarins is still desirable. Humic acid has been found to be an efficient catalyst for the synthesis of coumarins via the Pechmann reaction at 80oC under solvent-free conditions. The methodology enables the synthesis of structurally diverse coumarins from phenols and β-keto esters within 5-8 min in high yields (91-99%). The green, commercially available, inexpensive organocatalyst can be effectively recycled and reused five times with no significant dropdown in the yield of the product. The method reported has the advantages of high yield, no need for metal catalysts, short reaction time, simple operation, and green and reusable catalyst.
期刊介绍:
Aims & Scope
Letters in Organic Chemistry publishes original letters (short articles), research articles, mini-reviews and thematic issues based on mini-reviews and short articles, in all areas of organic chemistry including synthesis, bioorganic, medicinal, natural products, organometallic, supramolecular, molecular recognition and physical organic chemistry. The emphasis is to publish quality papers rapidly by taking full advantage of latest technology for both submission and review of the manuscripts.
The journal is an essential reading for all organic chemists belonging to both academia and industry.