Direct C H/C Li coupling of 1,2,4-triazines with C6F5Li followed by aza-Diels-Alder reaction as a pot, atom, and step economy (PASE) approach towards novel fluorinated 2,2′-bipyridine fluorophores
摘要:
An original pot, atom, and step economy (PASE) approach towards novel pentafluorophenyl-substltuted 2,2'-bipyridine fluorophores, as well as their triazine precursors via oxidative transition metal-free C-H/C-Li coupling reactions between 1,2,4-triazines and pentafluorophenyl lithium followed by aza-Diels-Alder reaction has first been reported. This reaction sequence has been found to afford a number of novel pentafiuorophenyl-modified heterocyclic ensembles of various architectures, such as perfluorophenyl-substituted 1,2,4-triazines, their dihydro derivatives, as well as 2,2'-bipyridines in good to excellent yields. The photophysical properties of the synthesized bipyridine fluorophores have been studied, and non-linear optics behavior of the most representative fluorophore has been disclosed on the basis of a positive solvatochromism effect observed. The novel fluorinated 2,2'-bipyridines synthesized are of particular interest in the design of advanced materials for molecular electronics and medicinal chemistry.
Facile synthesis of 6-aryl-3-pyridyl-1,2,4-triazines as a key step toward highly fluorescent 5-substituted bipyridines and their Zn(II) and Ru(II) complexes
摘要:
A wide series Of Substituted bipyridines were obtained through the synthesis of 1,2,4-triazines and their aza Diels-Alder reactions. The reported method facilitates the synthesis of functionally diverse bipyridines that provides fine-tuning of photophysical properties of new ligands and their Zn(II) and Ru(II) complexes. Some of substituted bipyridines exhibit 'off-on' fluorescence response toward Zn 2 cations. (C) 2008 Elsevier Ltd. All rights reserved.
From 1,2,4-triazines towards substituted pyridines and their cyclometallated Pt complexes
作者:Valery N. Kozhevnikov、Maria M. Ustinova、Pavel A. Slepukhin、Amedeo Santoro、Duncan W. Bruce、Dmitry N. Kozhevnikov
DOI:10.1016/j.tetlet.2008.04.138
日期:2008.6
A new, efficient methodology for the synthesis of substituted thienylpyridines includes the synthesis of 3-thienyl-1,2,4-triazines using simple heterocyclisation followed by easy transformation of the triazine ring to a pyridine through an aza Diels–Alder approach. A variety of substituted pyridines can be easily achieved using cheap, commercially available reagents such as bromoacetylarenes, aroyl