Impact of peripheral substituents in regioselective synthesis of position-10 or position-20 bromo-bacteriochlorins
Autor: | Shunichi Fukuzumi, Kei Ohkubo, Steve Zador, Walter A. Tabaczynski, Nayan J. Patel, Joseph R. Missert, Mykhaylo Dukh, Ravindra K. Pandey, Penny Joshi |
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Rok vydání: | 2017 |
Předmět: |
Reaction conditions
Pyridinium bromide 010405 organic chemistry Chemistry Stereochemistry Organic Chemistry Halogenation Regioselectivity 010402 general chemistry 01 natural sciences Biochemistry 0104 chemical sciences chemistry.chemical_compound Drug Discovery Chlorin Reactivity (chemistry) Derivative (chemistry) |
Zdroj: | Tetrahedron Letters. 58:851-854 |
ISSN: | 0040-4039 |
Popis: | Bacteriochlorins derived either from chlorophyll-a or bacteriochlorophyll-a on reacting with pyridinium bromide or N-bromosuccinimide (NBS) gave the corresponding 10- or 20-bromo analogues. In contrast to methyl bacteriopyropheophorbide-a, which afforded 10-bromo derivative, the 7-keto and 8-ketobacteriochlorins under similar reaction conditions gave the corresponding 20-bromo analogues exclusively. In both series, the nature of substituents present at position-3 did not make any difference in the reaction outcome. Density functional calculations were carried out to clarify the difference in reactions outcome. Density functional calculations were carried out to clarify the difference in reactivity of bromination at 10- and 20- meso positions. |
Databáze: | OpenAIRE |
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