The chemistry of [1,2,3]triazolo[1,5-a ]pyridines
The chemistry of [1,2,3]triazolo[1,5-a ]pyridines
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DOI：
10.1080/1475636021000005622
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发表时间：
2002-01-01
影响因子：
5.6
通讯作者：
Abarca-González, B
中科院分区：
文献类型：
--
作者：
Abarca-González, B
研究了[1，2，3]三唑并[1，5-a]吡啶类化合物的反应活性。三唑并吡啶与亲电体以两种不同的方式反应，得到3-取代的三唑并吡啶2，或产物3，由三唑环开环和分子氮的损失得到。三唑并吡啶可在-40℃被二异丙胺锂在乙醚中锂化，特别是得到7-锂硫代衍生物。溴三唑并吡啶在5位和7位具有亲核取代活性，在6位具有苯惰性。母体化合物1a易于氢化，高产率地得到四氢三唑并吡啶11a；当三唑并吡啶有取代基时，加氢反应强烈依赖于取代基的位置。类型18和26的三唑并吡啶叶立德与乙酰酯反应；这些反应受溶剂的性质和所使用的乙烯酯的影响，产生不同类型的加合物：稳定的双取代的19和20类型的三唑并吡啶叶立德、中氮并21或吡咯烯基吡唑并[5，1-a]吡啶22。还描述了这些叶立德的光化学，以及与MP和DMAD的光化学反应。报道了以三唑并吡啶为原料，两步合成2，2‘-联吡啶的新方法。
The reactivity of [1,2,3]triazolo[1,5- a ]pyridines 1 is described. Triazolopyridines react with electrophiles in two contrasting ways, giving 3-substituted triazolopyridines 2 , or products 3 , resulting from triazolo ring opening with loss of molecular nitrogen. The triazolopyridines can be lithiated at -40degreesC by lithium diisopropylamide in ether giving regiospecifically the 7-lithio derivative. Bromotriazolopyridines have activation towards nucleophilic substitution at position 5 and 7, and benzenoid inertness at position 6. The parent compound 1a is easily hydrogenated giving tetrahydrotriazolopyridine 11a in high yield; when the triazolopyridines have substituents, the hydrogenation reaction strongly depends on the position of the substituent. Triazolopyridinium ylides of type 18 and 26 react with acetylenic esters; these reactions are influenced by the nature of solvent and the acetylenic ester used, giving different types of adducts: stable disubstituted triazolo-pyridinium ylides of type 19 and 20 , indolizines 21 , or pyrroleninylpyrazolo[5,1- a ] pyridines 22 . Photochemistry, and photochemical reactions with MP and DMAD of these ylides are also described. A new way to 2,2'-bipyridines, in two steps from triazolopyridines is reported.