Regioselective reactions of methyl pyropheophorbide a with formaldehyde based on hydroxymethylation

Liu, Yang; Wu, Huiqiang; Zhang, Xiao; Pan, Qiang; Wang, Xiangmin; Wei, Peng; Yin, Jie; Li, Guizhi; Li, Jiazhu; Wang, Jinjun

doi:10.1007/s11696-017-0376-4

Cited by 3 publications

(2 citation statements)

References 26 publications

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“…In contrast, after reacting with diethyl cyanomethyl‐phosphonate in the presence of MeONa, cyanomethylene chlorins 12 (91% yield) and 13 (87% yield) can be obtained gently from 10 and 11 , respectively (Scheme ). It is worth noting that the same HWE reaction of MMPP a 9 did not give the 13 1 ‐cyanomethylene product 14 , which might be due to the lower reactivity of 9 compared to MPP a 1 , in spite of the fact that the only difference of these two compounds is the group on C3 . The structures of 12 and 13 were also confirmed carefully through an analysis of their NMR spectra (see Supporting information).…”

Section: Resultsmentioning

confidence: 89%

Efficient Synthesis of Long‐wavelength Absorbing Cyanochlorophyll a Derivatives via Stereoselective Horner–Wadsworth–Emmons Reaction

Wang

Liu

et al. 2020

Bulletin Korean Chem Soc

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In this article, we report the stereoselective Horner-Wadsworth-Emmons reaction of reactive carbonyl-substituted chlorophyll a derivatives with diethyl cyanomethylphosphonate. We found that the formyl or keto group at the chlorin periphery can react stereoselectively with phosphonate carbanions to produce a series of cyanomethylenesubstituted chlorins with predominantly E geometry. Considering that no consistent records are available in the literature on the results of the allomerization of methyl pyropheophorbide a, we propose a reliable process for the transformation of this chlorophyll derivative. Our methodology represents a simple and efficient way for the preparation of novel, differently functionalized long-wavelength absorbing chlorins, those can be applied for photodynamic therapy, solar cells, and other relevant purposes.

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Section: Resultsmentioning

confidence: 89%

Efficient Synthesis of Long‐wavelength Absorbing Cyanochlorophyll a Derivatives via Stereoselective Horner–Wadsworth–Emmons Reaction

Wang

Liu

et al. 2020

Bulletin Korean Chem Soc

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“…In addition to the aforementioned Chls possessing vinyl groups, many vinyl‐chlorins have been prepared by chemically modifying natural Chls, and their physical properties have been investigated. In a series of (zinc) methyl pyropheophorbides, a vinyl (or methylene) group was substituted at the 3‐, 7‐, 8‐ (20), 12‐ (21,22), 13 1 ‐ (23), 13 2 ‐ (24), and 20‐positions (25) (see Fig. 1B), and their physical properties were compared with those of the unsubstituted, methylated, and ethylated counterparts.…”

Section: Introductionmentioning

confidence: 99%

Substituted Methylenation at the 13²‐Position of a Chlorophyll‐a Derivative via Mixed Aldol Condensation, Optical Properties of the Synthetic Bacteriochlorophyll‐d Analogs, and Self‐aggregation of Their Zinc Complexes^†

Takeda

Kitagawa

Tamiaki

2022

Photochem & Photobiology

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Chlorophyll-a derivatives possessing a substituted methylene group at the 13 2 -position were prepared by the mixed aldol condensation of methyl 3-hydroxymethyl-pyropheophorbide-a with aldehydes bearing a methyl, p-nitro/cyanophenyl, or pentafluorophenyl group. Their electronic absorption spectra were dependent on the substituents at the methylene terminal. The Soret bands were broadened by increasing the group electronegativity of the substituents, which was ascribable to the charge transfer from the core chlorin to the peripheral substituent in a molecule. Although their Qy absorption and fluorescence emission bands resembled each other, the emission intensities decreased with an increase in the electronegativity because of intramolecular electron transfer quenching. Some of their zinc complexes self-aggregated in a less polar organic solvent to give red-shifted and broadened absorption bands with intense circular dichroism couplets, which were similar to those of bacteriochlorophyll-c/d aggregates in natural chlorosomes as the main lightharvesting antennas of green photosynthetic bacteria and their models. The J-aggregation was suppressed with an enhancement in the size of the 13 2 -substituents.

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Stereoselective self-aggregation of synthetic zinc 31-epimeric bacteriochlorophyll-d analogs possessing a methylene group at the 132-position as models of green photosynthetic bacterial chlorosomes

Fujiwara

Tamiaki

2019

Photochem Photobiol Sci

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Regioselective reactions of methyl pyropheophorbide a with formaldehyde based on hydroxymethylation

Cited by 3 publications

References 26 publications

Efficient Synthesis of Long‐wavelength Absorbing Cyanochlorophyll a Derivatives via Stereoselective Horner–Wadsworth–Emmons Reaction

Efficient Synthesis of Long‐wavelength Absorbing Cyanochlorophyll a Derivatives via Stereoselective Horner–Wadsworth–Emmons Reaction

Substituted Methylenation at the 13²‐Position of a Chlorophyll‐a Derivative via Mixed Aldol Condensation, Optical Properties of the Synthetic Bacteriochlorophyll‐d Analogs, and Self‐aggregation of Their Zinc Complexes^†

Stereoselective self-aggregation of synthetic zinc 31-epimeric bacteriochlorophyll-d analogs possessing a methylene group at the 132-position as models of green photosynthetic bacterial chlorosomes

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Regioselective reactions of methyl pyropheophorbide a with formaldehyde based on hydroxymethylation

Cited by 3 publications

References 26 publications

Efficient Synthesis of Long‐wavelength Absorbing Cyanochlorophyll a Derivatives via Stereoselective Horner–Wadsworth–Emmons Reaction

Efficient Synthesis of Long‐wavelength Absorbing Cyanochlorophyll a Derivatives via Stereoselective Horner–Wadsworth–Emmons Reaction

Substituted Methylenation at the 132‐Position of a Chlorophyll‐a Derivative via Mixed Aldol Condensation, Optical Properties of the Synthetic Bacteriochlorophyll‐d Analogs, and Self‐aggregation of Their Zinc Complexes†

Stereoselective self-aggregation of synthetic zinc 31-epimeric bacteriochlorophyll-d analogs possessing a methylene group at the 132-position as models of green photosynthetic bacterial chlorosomes

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Substituted Methylenation at the 13²‐Position of a Chlorophyll‐a Derivative via Mixed Aldol Condensation, Optical Properties of the Synthetic Bacteriochlorophyll‐d Analogs, and Self‐aggregation of Their Zinc Complexes^†