As PFOS, PFOA and their derivatives were banned according to the Stockholm Convention for their potential bioaccumulation and toxicity, people attempted to substitute the legacy fluorosurfactants with short-chain ones...As PFOS, PFOA and their derivatives were banned according to the Stockholm Convention for their potential bioaccumulation and toxicity, people attempted to substitute the legacy fluorosurfactants with short-chain ones. Although short-chain alternatives can alleviate bioaccumulation, surface activity was compromised. Fluorine industry kept seeking for effective solution. In this work, we prepared and investigated a series of fluoroether betaine surfactants for their surface activity and spreading property. The role of oxygen on surface activity was discussed. We found that insertion of oxygen atoms into fluorinated chain could increase hydrophobicity and thus enhance surface activity. The contribution of one oxygen is approximately half of that of a difluoromethylene group by experience. Moreover, introducing oxygen diversified the structure to fill in the gap of surface activity between short and long fluorosurfactants. In summary, this work provided basic knowledge for molecular design.展开更多
The deoxyfluorination of carboxylic,sulfonic,phosphinic acids and phosphine oxides is a fundamentally important approach to access acyl fluorides,sulfonyl fluorides and phosphoric fluorides,thus the development of ine...The deoxyfluorination of carboxylic,sulfonic,phosphinic acids and phosphine oxides is a fundamentally important approach to access acyl fluorides,sulfonyl fluorides and phosphoric fluorides,thus the development of inexpensive,stable,easy-to-handle,versatile,and efficient deoxyfluorination reagents is highly desired.Herein,we report the use of potassium salts of perfluoroalkyl ether carboxylic acids(PFECA)featuring CF_(2)0 units as deoxyfluorination reagents,which are generated mainly as by-products in the manufacture of hexafluoropropene oxide(HFPO).The synthesis of acyl fluorides,sulfonyl fluorides and phosphoric fluorides can be realized via carbonic difluoride(COF_(2))generated in situ from thermal degradation of the PFECA salt.展开更多
The importance of CF3-containing molecules in pharmaceuticals, agrochemicals and materials intrigues the intense interest in synthetic methodology of these compounds. With a purpose to enrich trifluoromethylation meth...The importance of CF3-containing molecules in pharmaceuticals, agrochemicals and materials intrigues the intense interest in synthetic methodology of these compounds. With a purpose to enrich trifluoromethylation methodology, we carefully examined the substrate scope of hydroxytrifluoromethylation of alkenes using iodotrifluoromethane, and the reaction provided β-trifluoromethyl alcohols in good yields under extremely mild conditions without catalysts. We found that our reaction can be applied to not only styrenes but also various aliphatic alkenes with excellent selectivity;no ketone was detected in most of our cases. Another feature of our discovery is “simple”. The reaction was carried out in air, irradiated by visible light, at room temperature and most importantly no catalyst was needed. A solution of CF3I in DMSO was used as the facile trifluoromethylating reagent, which simplified the utilization of gaseous CF3I. Based on 19F NMR spectroscopy, we observed a halogen bond between CF3I and tertiary amine in this reaction. The interaction may promote single electron transfer by the visible light irradiation.展开更多
基金Key Program of National Natural Science Foundation of China(No.21737004)the National Key Research and Development Program of China(No.2021YFF0701700)+1 种基金Science and Technology Department of Fujian Province(No.2020T3020)Science and Technology Bureau of Sanming City(No.2021-G-50)for financial support。
文摘As PFOS, PFOA and their derivatives were banned according to the Stockholm Convention for their potential bioaccumulation and toxicity, people attempted to substitute the legacy fluorosurfactants with short-chain ones. Although short-chain alternatives can alleviate bioaccumulation, surface activity was compromised. Fluorine industry kept seeking for effective solution. In this work, we prepared and investigated a series of fluoroether betaine surfactants for their surface activity and spreading property. The role of oxygen on surface activity was discussed. We found that insertion of oxygen atoms into fluorinated chain could increase hydrophobicity and thus enhance surface activity. The contribution of one oxygen is approximately half of that of a difluoromethylene group by experience. Moreover, introducing oxygen diversified the structure to fill in the gap of surface activity between short and long fluorosurfactants. In summary, this work provided basic knowledge for molecular design.
基金the National Natural Science Foundation of China(Nos.21737004,21672239,and 21421002)Chinese Academy of Science(KF-STS-QYZX-068)is gratefully acknowledged.
文摘The deoxyfluorination of carboxylic,sulfonic,phosphinic acids and phosphine oxides is a fundamentally important approach to access acyl fluorides,sulfonyl fluorides and phosphoric fluorides,thus the development of inexpensive,stable,easy-to-handle,versatile,and efficient deoxyfluorination reagents is highly desired.Herein,we report the use of potassium salts of perfluoroalkyl ether carboxylic acids(PFECA)featuring CF_(2)0 units as deoxyfluorination reagents,which are generated mainly as by-products in the manufacture of hexafluoropropene oxide(HFPO).The synthesis of acyl fluorides,sulfonyl fluorides and phosphoric fluorides can be realized via carbonic difluoride(COF_(2))generated in situ from thermal degradation of the PFECA salt.
基金the National Natural Science Foundation of China (Nos.21672239,21737004 and 21421002)Key Laboratory of Photochemical Conversion and Optoelectr onic Materials,TIPC,CAS,the Sanming Institute of Fluorochemical Industry (Nos.FCIT201704GR,FCIT201705GR,FCIT201701BR)STS Program of Chinese Academy of Science (KF-STS-QYZX-068).
文摘The importance of CF3-containing molecules in pharmaceuticals, agrochemicals and materials intrigues the intense interest in synthetic methodology of these compounds. With a purpose to enrich trifluoromethylation methodology, we carefully examined the substrate scope of hydroxytrifluoromethylation of alkenes using iodotrifluoromethane, and the reaction provided β-trifluoromethyl alcohols in good yields under extremely mild conditions without catalysts. We found that our reaction can be applied to not only styrenes but also various aliphatic alkenes with excellent selectivity;no ketone was detected in most of our cases. Another feature of our discovery is “simple”. The reaction was carried out in air, irradiated by visible light, at room temperature and most importantly no catalyst was needed. A solution of CF3I in DMSO was used as the facile trifluoromethylating reagent, which simplified the utilization of gaseous CF3I. Based on 19F NMR spectroscopy, we observed a halogen bond between CF3I and tertiary amine in this reaction. The interaction may promote single electron transfer by the visible light irradiation.