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| Thesis Name： |
Efficient synthesis of dipyrromethanes and their use in the preparation of porphyrins |
| Usage： |
Ceric ammonium nitrate, pyrrole, dipyrromethane, porphyrin |
| Keyword： |
Ceric ammonium nitrate, pyrrole, dipyrromethane, porphyrin |
| Remarks： |
meso-Substituted dipyrromethanes are important precursors for the synthesis of meso-substituted porphyrins,[1] expanded porphyrins, and porphyrin analogues.[2] Several one-flask methods have been reported for the synthesis of meso-substituted dipyrromethanes by the condensation of an aldehyde and pyrrole using various combinations of acids and solvents,[3-15] such as p-Toluenesulfonic acid, propionic acid, trifluoroacetic acid (TFA) and BF3·etherate in the presencet of menthol, dichloromethane or in the absence of any other solvent, etc. These methods have afforded meso-substituted dipyrromethanes bearing many types of functional groups. However, among the above catalysts used in condensation reaction, some are expensive, some are inconvenient to use and some are of lower yield of reaction.
In recent years, ceric ammonium nitrate (CAN) has been exploited extensively in organic reactions such as oxidation, oxidative addition, nitration, photooxidation, deprotection, and graft polymerization, etc.[16] Recently Ji reported the use of CAN as a catalyst in Michael addition of indole to a,b-unsaturated ketones.[17] However, the use of CAN as a catalyst in the synthesis of dipyrromethanes under neutral conditions has not been reported. In this report we describe a condensation reaction of pyrrole with aldehydes using a catalytic amount of ceric ammonium nitrate at room temperature in the absence of any other solvent, which provides an efficient route to the synthesis of 5-substituted dipyrromethanes. |
| Original file： |
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Promulgator Detail |
| Full name: |
hichem |
| Country: |
CN |
| City: |
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| Company Name: |
hichem |
| Homepage: |
http://www.teloon.com |
| E-mail: |
reply |
| Phone: |
86-411-82819585 |
| Fax: |
86-411-82819612 |
| Company Address: |
Renming Road, Dalian city, Lianning pro,china |
| Zip/Postal Code: |
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| Introduction: |
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