512-85-6Relevant academic research and scientific papers
Singlet Oxygen Generation from a Water-Soluble Hypervalent Iodine(V) Reagent AIBX and H2O2: An Access to Artemisinin
Hu, Ze-Nan,Shen, Hui-Jie,Zhang, Chi
, (2021/06/21)
Herein, we report an efficient method for the chemical generation of 1O2 by treatment of H2O2 with AIBX, a highly water-soluble, bench-stable, recyclable hypervalent iodine(V) reagent developed by our group. The generation of 1O2 was confirmed by the following results: (1) capture of 1O2 with the sodium salt of anthracene-9,10-bis(ethanesulfonate) produced the corresponding endoperoxide and (2) TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) produced by the oxidation of 2,2,6,6-tetramethylpiperidine with 1O2 generated using the AIBX/H2O2 system was detected by electron spin resonance spectroscopy. To illustrate the potential utility of this method for organic synthesis, we used the AIBX/H2O2 system to perform typical reactions of 1O2: [2 + 2]/[4 + 2] cycloadditions, Schenck ene reactions, and heteroatom oxidation reactions, which afforded the corresponding products in high yields. Moreover, we used the method to synthesize the antimalarial drug artemisinin. Finally, we demonstrated that AIBX could be regenerated after the reaction by means of a workup involving extraction and removal of water to obtain a precursor of AIBX, which could then be re-oxidized.
Nature inspired singlet oxygen generation to access α-amino carbonyl compounds: Via 1,2-acyl migration
Schilling, Waldemar,Zhang, Yu,Sahoo, Prakash Kumar,Sarkar, Samir Kumar,Gandhi, Sivaraman,Roesky, Herbert W.,Das, Shoubhik
supporting information, p. 379 - 387 (2021/01/28)
We have discovered chlorophyll catalyzed 1,2-acyl migration reactions to achieve α-amino carbonyl compounds directly from the enaminones. In general, singlet oxygen is generated during photosynthesis in the photosystem II center. This singlet oxygen can readily react with the unsaturated double bonds present in biomolecules. This reactivity intrigued us to apply this concept towards unsaturated enaminones and others to achieve highly valuable compounds. Indeed, this photosensitizer is very cheap, commercially available, main group metal based and provided excellent efficiency for singlet oxygen mediated chemistry by achieving high turnover number (TON) > 300 with a high turnover frequency (TOF) of 50 h-1. Finally, a combination of DFT calculations and detailed mechanistic experiments provided the exact role of the photosensitizer and clear insights into the reaction.
8,8′-(Benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(quinolin-4(1H)-one): a twisted photosensitizer with AIE properties
Broumidis, Emmanouil,Jones, Callum M. S.,Kourtellaris, Andreas,Koutentis, Panayiotis A.,Koyioni, Maria,Lloyd, Gareth O.,Marques-Hueso, Jose,Vilela, Filipe
, p. 29102 - 29107 (2021/10/08)
A new benzothiadiazole (BTZ) luminogen is preparedviathe Suzuki-Miyaura Pd-catalysed C-C cross-coupling of 8-iodoquinolin-4(1H)-one and a BTZ bispinacol boronic ester. The rapid reaction (5 min) affords the air-, thermo-, and photostable product in 97% yield as a yellow precipitate that can be isolated by filtration. The luminogen exhibits aggregated-induced emission (AIE) properties, which are attributed to its photoactive BTZ core and nonplanar geometry. It also behaves as a molecular heterogeneous photosensitizer for the production of singlet oxygen under continuous flow conditions.
COVALENT ORGANIC FRAMEWORKS AND APPLICATIONS AS PHOTOCATALYSTS
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Paragraph 00145; 00162-00164, (2021/05/21)
Described herein are covalent organic frameworks. The covalent organic frameworks have unique structural and physical properties, which lends them to be versatile in a number of different applications and uses. In one aspect, the covalent organic frameworks are composed of a plurality of fused aromatic groups and electron-deficient chromophores. The covalent organic frameworks are useful as photocatalysts in a number of different applications.
Singlet-Oxygen Generation by Peroxidases and Peroxygenases for Chemoenzymatic Synthesis
Ingenbosch, Kim N.,Quint, Stephan,Dyllick-Brenzinger, Melanie,Wunschik, Dennis S.,Kiebist, Jan,Süss, Philipp,Liebelt, Ute,Zuhse, Ralf,Menyes, Ulf,Scheibner, Katrin,Mayer, Christian,Opwis, Klaus,Gutmann, Jochen S.,Hoffmann-Jacobsen, Kerstin
, p. 398 - 407 (2020/10/09)
Singlet oxygen is a reactive oxygen species undesired in living cells but a rare and valuable reagent in chemical synthesis. We present a fluorescence spectroscopic analysis of the singlet-oxygen formation activity of commercial peroxidases and novel peroxygenases. Singlet-oxygen sensor green (SOSG) is used as fluorogenic singlet oxygen trap. Establishing a kinetic model for the reaction cascade to the fluorescent SOSG endoperoxide permits a kinetic analysis of enzymatic singlet-oxygen formation. All peroxidases and peroxygenases show singlet-oxygen formation. No singlet oxygen activity could be found for any catalase under investigation. Substrate inhibition is observed for all reactive enzymes. The commercial dye-decolorizing peroxidase industrially used for dairy bleaching shows the highest singlet-oxygen activity and the lowest inhibition. This enzyme was immobilized on a textile carrier and successfully applied for a chemical synthesis. Here, ascaridole was synthesized via enzymatically produced singlet oxygen.
Synthesis and application of photosensitizer
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Paragraph 0051-0053, (2020/09/23)
The invention relates to the field of organic synthesis and biological medicine, particularly to synthesis of a class of photosensitizers with aggregation-induced emission properties, and applicationof the photosensitizers loaded on a solid-phase material in synthesis of bioactive molecules or medical intermediates and application of the photosensitizers in the medical fields of photodynamic therapy, immunogenic cell death and the like. According to the invention, the photosensitizer can effectively generate singlet oxygen under an illumination condition; compared with the traditional photosensitizer, the photosensitizer of the invention has the following characteristics that the phenomena of aggregation fluorescence quenching and aggregation singlet oxygen generation capacity reduction are avoided; and when the photosensitizer is applied to synthesis of bioactive molecules or medical intermediates, the photosensitizer has the advantages of reusability, simple and convenient post-treatment and the like, and the characteristics are not possessed by traditional photosensitizers.
Efficient generation of singlet oxygen by perylene diimide photosensitizers covalently bound to conjugate polymers
Blacha-Grzechnik, Agata,Drewniak, Anna,Walczak, Krzysztof Z.,Szindler, Marek,Ledwon, Przemyslaw
, (2019/11/03)
New conjugated polymers with perylene diimides (PDI) as pendant groups were synthesized and deposited on glass substrates by the spin coating. The resulting thin films were characterized by UV–vis, Raman spectroscopy, atomic force microscopy and profilometry. It was shown that PDI photosensitizers retain its photoactivity after covalent immobilization and the formed layers can be applied as efficient and environmentally stable source of singlet oxygen, 1O2, as tested with 1,3-diphenylisobenzofuran (DPBF) specific trap. Additionally, α-terpinene heterogeneous photooxidation was studied as the practical use of singlet oxygen generated by this novel PDI-based materials. The use of such heterogeneous source of singlet oxygen can be beneficial for the fine chemicals synthesis, due to simplified products isolation and purification step.
Discrete Ti?O?Ti Complexes: Visible-Light-Activated, Homogeneous Alternative to TiO2 Photosensitisers
Behm, Kira,Fazekas, Eszter,Paterson, Martin J.,Vilela, Filipe,McIntosh, Ruaraidh D.
, p. 9486 - 9494 (2020/07/13)
A series of novel bimetallic TiIV amine bis(phenolate) complexes was synthesised and fully characterised. X-ray crystallography studies revealed distorted octahedral geometries around the Ti centres with single or double oxo-bridges connecting the two metals. These robust, air- and moisture-stable complexes were employed as photosensitisers generating singlet oxygen following irradiation with visible light (420 nm) LED module in a commercial flow reactor. All five complexes showed high activity in the photo-oxygenation of α-terpinene and achieved complete conversion to ascaridole in four hours at ambient temperature. The excellent selectivity of these photosensitisers towards ascaridole (vs. transformation to p-cymene) was demonstrated with control experiments using a traditional TiO2 catalyst. Further comparative studies employing the free pro-ligands as well as a monometallic analogue highlighted the importance of the ‘TiO2-like’ moiety in the polymetallic catalysts. Computational studies were used to determine the nature of the ligand to metal charge transfer (LMCT) states and singlet–triplet gaps for each complex, the calculated trends in the UV-vis absorption spectra across the series agreed well with the experimental results.
Robust Organic Photosensitizers Immobilized on a Vinylimidazolium Functionalized Support for Singlet Oxygen Generation under Continuous-Flow Conditions
Kobayashi, Shū,Koumura, Nagatoshi,Masuda, Koichiro,Onozawa, Shun-Ya,Sato, Kazuhiko,Shimada, Shigeru,Wang, Yao
supporting information, p. 497 - 501 (2020/03/13)
Rose Bengal was immobilized on a vinylimidazolium functionalized support, and the heterogeneous organic photosensitizer thus prepared was applied for photooxidation reactions of organic molecules under continuous-flow conditions. Substituents of the cation part of the support were found to play a crucial role in determining the lifetime of the catalyst. More than 11 days continuous operation of a flow reaction was achieved.
A method to determine the correct photocatalyst concentration for photooxidation reactions conducted in continuous flow reactors
Gremetz, Sylvain,Horn, Clemens R.
supporting information, p. 871 - 879 (2020/05/14)
When conducting a photooxidation reaction, the key question is what is the best amount of photocatalyst to be used in the reaction? This work demonstrates a fast and simple method to calculate a reliable concentration of the photocatalyst that will ensure an efficient reaction. The determination is based on shifting the calculation away from the concentration of the compound to be oxidized to utilizing the limitations on the total light dose that can be delivered to the catalyst. These limitations are defined by the photoflow setup, specifically the channel height and the emission peak of the light source. This method was tested and shown to work well for three catalysts with different absorption properties through using LEDs with emission maxima close to the absorption maximum of each catalyst.
