RESUMO
This review summarizes the applications of organophosphates in organic synthesis. After a brief introduction, it discusses cross-coupling reactions, including both transition-metal-catalyzed and transition-metal-free substitution reactions. Subsequently, oxidation and reduction reactions are described. In addition, this review highlights the applications of organophosphates in the synthesis of natural compounds, demonstrating their versatility and importance in modern synthetic chemistry.
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Palladium-catalyzed Suzuki reactions of brominated flavin derivatives (5-deazaflavins, alloxazines, and isoalloxazines) with boronic acids or boronic acid esters that occur readily under mild conditions were shown to be an effective tool for the synthesis of a broad range of 7/8-arylflavins. In general, the introduction of an aryl/heteroaryl group by means of a direct C-C bond has been shown to be a promising approach to tuning the photophysical properties of flavin derivatives. The aryl substituents caused a bathochromic shift in the absorption spectra of up to 52 nm and prolonged the fluorescence lifetime by up to 1 order of magnitude. Moreover, arylation of flavin derivatives decreased their ability to generate singlet oxygen.
Assuntos
Ácidos Borônicos , Ésteres , Catálise , Ésteres/química , Ácidos Borônicos/química , Paládio/químicaRESUMO
This review summarizes the current state-of-the-art procedures in terms of the preparation of N-arylindoles. After a short introduction, the transition-metal-free procedures available for the N-arylation of indoles are briefly discussed. Then, the nickel-catalyzed and palladium-catalyzed N-arylation of indoles are both discussed. In the next section, copper-catalyzed procedures for the N-arylation of indoles are described. The final section focuses on recent findings in the field of biologically active N-arylindoles.
RESUMO
We studied the reactions of vinyl phosphates and vinyl phosphordiamidates containing an ester functional group with organometallic reagents. We found that the functionalized vinyl phosphates were smoothly converted into tri- and tetrasubstituted buta-1,3-dienes via the reaction with aryllithium reagents. Moreover, the vinyl phosphordiamidates were converted into α,ß-unsaturated ketones using Grignard reagents. Based on the performed experiments, we proposed a reaction mechanism, which was confirmed by means of the isolation of key intermediates.