radical precursors, the O-acyl derivatives of 1-hydroxypyridine-2(1H)-thione 2, have been studied in detail for more than a decade, to date nothing has been reported on the solid state or the solution geometries of these molecules or the analogous oxo derivatives, the pyridones 7, 8. In view of this, selected O-alkyl and O-acyl derivatives of pyridinethiones and of 2-(1H)pyridones have been prepared
disclose here that N-alkenoxypyridinium salts, generated readily upon gold-catalyzed additions of protonated pyridine N-oxide to C-C triple bonds of unactivated terminal alkynes, display versatile enolate umpolung chemistry upon heating and react with tethered arene nucleophiles in an SN2' manner. In a synthetically efficient one-pot, two-step process, this chemistry enables expedient preparation of valuable
与烯醇化物对应物相比,烯醇化物 umpolung 反应性为构建普遍存在的羰基化合物提供了有价值且可能独特的替代方案。我们在此公开了 N-链烯氧基吡啶鎓盐,在金催化下将质子化吡啶 N-氧化物与未活化末端炔烃的 CC 三键加成后很容易生成,在加热时显示出多功能的烯醇化极性化学,并以 SN2' 方式与系链芳烃亲核试剂反应。在合成高效的一锅两步法中,这种化学反应能够方便地从易于获得的芳基取代的线性炔烃中方便地制备有价值的苯并稠合七元/八元环酮,包括 O-/N-杂环酮基材。反应收率可达87%。
Synthesis of <i>N</i>-(2-pyridyl)imidazolidin-2-ones and 1-(2-pyridyl)-2,3,7,8-tetrahydro-1<i>H</i>-imidazo[2,1-<i>b</i>][1,3,5]triazepin-5(6<i>H</i>)-ones with potential biological activities
作者:Łukasz Balewski、Franciszek Sączewski、Maria Gdaniec、Patrick J. Bednarski、Izabela Jara
DOI:10.1515/hc-2013-0125
日期:2013.10.1
1-(2-pyridyl)imidazolidin-2-one and 1-(2-pyridyl)-2,3,7,8-tetrahydro-1H-imidazo[2,1-b]- [1,3,5]triazepin-5(6H)-one derivatives were prepared from substituted pyridine or quinoline N-oxides and 2-chloro-4,5-dihydroimidazole by means of the α-ureation and α-amination reactions. The α-ureation reaction of pyridine and quinoline N-oxides was studied theoretically by means of quantum chemical calculations