Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Mikhail E. Minyaev and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• pyranone ring leading to the formation of α-hydroxy-1,2-diketones. This phototransformation is initiated by an excited state intramolecular proton transfer (ESIPT) process. In most cases the resulting α-hydroxy-1,2-diketones are unstable and their further reactions open access to various original products

• as a result of ESIPT-induced reactions (Scheme 1A and B). At the same time, both directions of phototransformation are realized for terarylenes with furan, pyrrole, and oxazolone-bridge fragments (Scheme 1C). However, the suppression of the ESIPT process in such systems makes it possible to perform

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• established by X-ray diffraction. Keywords: allomaltol; ESIPT process; photochemistry; pyrazoles; terarylenes; Introduction The investigation of the photochemical behavior of organic products is a significant part of modern materials science and technology. The UV-induced processes are extensively employed

• considered photoprocess. Probably, the DMF molecule forms an intermolecular hydrogen bond with the hydroxy group of the allomaltol fragment leading to complete suppression of the ESIPT process. Finally, AcOH was used as a solvent for the photochemical synthesis of α-hydroxy-1,2-diketone 14a. The starting

Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

• Luna Kono,
• Yuma Nakagawa,
• Ayako Fujimoto,
• Ryo Nishimura,
• Yohei Hattori,
• Toshiki Mutai,
• Nobuhiro Yasuda,
• Kenichi Koizumi,
• Satoshi Yokojima,
• Shinichiro Nakamura and
• Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

• ), acetonitrile (orange line). The absorption at the excited wavelength of each solution was adjusted to 0.05. (emission peaks at 740 nm is attributed to the 2nd order diffracted excitation light.) (a) The energy diagram of the ESIPT process of 1. (b) ESIPT fluorescence quenching upon UV light (λ = 313 nm

An uracil-linked hydroxyflavone probe for the recognition of ATP

• Márton Bojtár,
• Péter Zoltán Janzsó-Berend,
• Dávid Mester,
• Dóra Hessz,
• Mihály Kállay,
• Miklós Kubinyi and
• István Bitter

Beilstein J. Org. Chem. 2018, 14, 747–755, doi:10.3762/bjoc.14.63

• electric fields generated by ions and molecules in solution. This property along the ESIPT process (excited state intramolecular proton transfer) [35] makes them ideal for ratiometric environment-sensitive probes and sensors [36][37][38][39][40][41][42][43]. Among them the 4’-dimethylamino derivative (DMHF