Facile synthesis of 131-oxo-porphyrins possessing reactive 3-vinyl or 3-formyl group, protochlorophyll-a/d derivatives by 17,18-dehydrogenation of chlorins
✍ Scribed by Hitoshi Tamiaki; Takuya Watanabe; Tomohiro Miyatake
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 94 KB
- Volume
- 03
- Category
- Article
- ISSN
- 1088-4246
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✦ Synopsis
Methyl protopyropheophorbides-a/d were prepared by modification of readily available chlorophyll-a. The key step was oxidation of 131-oxo-chlorin to the corresponding porphyrin, and 2,3-dichloro-5,6-dicyano-p-benzoquinone was effective for 17,18-dehydrogenation. A reduction in oxidation potential of the chlorin was necessary for the oxidation. Facile oxidation was achieved by insertion of zinc as the central metal, reduction of the 13-carbonyl group and/or aggregation by high concentration. The synthetic 131-oxo-porphyrins had vinyl and formyl groups at the 3-position. These groups were very reactive in the molecule and selectively converted to other functional groups.