Novel photosensitizers for the E/Z-isomerization of trienes. Part 1. Syntheses and application
摘要:
Uranine and its thioxanthene and selenoxanthene analogues, as well as the disodium salts of o-(6-hydroxy-3-oxo-3H-xanthen-9-yl)benzenesulphonic acid and its thioxanthene and selenoxanthene analogues, show different photosensitizer properties in the E/Z-isomerization of trienes. This has been verified by applying them to the technically useful conversion of tachysterol into previtamin D. The syntheses of the novel photosensitizers with thioxanthene and selenoxanthene moieties are also described.
Keimatsu; Yokota; Satoda, Yakugaku Zasshi/Journal of the Pharmaceutical Society of Japan, 1933, vol. 53, p. 993,1029; dtsch. Ref. S. 203, 206
作者:Keimatsu、Yokota、Satoda
DOI:——
日期:——
Microwave-assisted Cu2O-catalyzed one-pot synthesis of symmetrical diaryl selenides from elemental selenium
作者:Shaozhong Zhang、Kranthi Karra、Christina Heintz、Erica Kleckler、Jin Jin
DOI:10.1016/j.tetlet.2013.06.117
日期:2013.8
A novel and simple microwave-assisted one-pot protocol to prepare symmetrical diary] selenides has been developed. A cross-coupling reaction between aryl iodide and elemental selenium takes place in the presence of KOH and a catalytic amount of Cu2O/NH2CH2CH2NH2, leading to C-Se bond formation. The reactions are highly efficient with a reaction time of 1 h under microwave irradiation and yields from 50% to 90%. Published by Elsevier Ltd.
Synthesis and Reactivity of Dibenzoselenacycloheptynes
作者:Gabriela de Almeida、Lisa C. Townsend、Carolyn R. Bertozzi
DOI:10.1021/ol401225n
日期:2013.6.21
Dibenzoselenacycloheptynes were prepared in three steps from commercially available reagents and trapped in situ with benzyl azide to form the corresponding triazoles. Surprisingly, the dibenzoselenacycloheptynes also abstracted hydrogen atoms from solvents such as THF or toluene, forming dibenzoselenacycloheptene products. These alkenyl compounds arise from a hydrogen transfer reaction from solvent to the unisolable Intermediate, and we postulate that the reaction proceeds via a radical mechanism originating from the strained alkynyl bond that has unusually high radical character.
Synthesis of 9-oxoselenoxanthenium and triarylselenonium hexafluorophosphates
作者:V. A. Loskutov、S. V. Balina、V. V. Russkikh、V. V. Shelkovnikov
DOI:10.1134/s1070363215050163
日期:2015.5
The selenoxides forming 9-oxoselenoxanthenium and triaryl selenonium hexafluorophosphates via interaction with heptyl phenyl ether and anisole in the MeSO3H-P2O5 mixture followed by treatment with KPF6 have been obtained via selenoxantene-9-one and diphenyl selenide derivatives oxidation with m-chloroperoxybenzoic acid or hydrogen peroxide.
Selenium dioxide promoted dinitrogen extrusion/direct selenation of arylhydrazines and anilines
作者:Mohammad Yaqoob Bhat、Atul Kumar、Qazi Naveed Ahmed
DOI:10.1016/j.tet.2020.131105
日期:2020.4
A novel, efficient, economical strategy for the coupling and direct selenation of arylhydrazines to selenides using SeO2 has been developed. Our method employs SeO2 as the selenium source with hydrazines as coupling reactants to generate selenides via dinitrogen extrusion. This reagent also helped to generate ArSesubstitued aniline derivatives via C– H functionalization reaction in good yields. The