Regioselective Synthesis of 1-Aryl-3,4-substituted/annulated-5-(methylthio)pyrazoles and 1-Aryl-3-(methylthio)-4,5-substituted/annulated Pyrazoles
摘要:
Highly efficient and regioselective synthesis of 1-aryl-3,4-substituted/annulated-5-(methylthio)-pyrazoles and 1-aryl-3-(methylthio)-4,5-substituted/annulated pyrazoles has been reported via cyclocondensation of arylhydrazines with either alpha-oxoketene dithioacetals or beta-oxodithioesters.
Sulfhydrolysis of Acyl Ketene Dithioacetals: A Convenient Synthesis of β-Oxodithioesters
摘要:
beta-Oxodithioesters are obtained in. good yields from acyl ketenedithioacetals on treatment with hydrogen sulphide in the presence of boron trifluoride etherate in refluxing dioxane.
Alkylation of aryl 3-oxopropanedithioate and 3-amino-1-aryl-3-thioxo-1-propanones as an effective tool for the construction of differently substituted thiophenes and annulated thiophenes
The alkylation of aryl 3-oxopropanedithioate with α-haloketones under different reaction conditions afforded substituted aryl[2-(methylsulfanyl)-4-phenyl-3-thienyl]methanones and [3-aryl-5-(methylsulfanyl)-2-thienyl](phenyl)methanones. The same strategy was extended to 3-amino-1-aryl-3-thioxo-1-propanones to afford aryl[2-amino-4-phenyl-3-thienyl]methanones and ethyl 3-phenyl-5-piperidino-2-thiophene
p -Toluenesulfonic acid-catalyzed metal-free formal [4 + 1] heteroannulation via N H/O H/S H functionalization: One-pot access to 2-aryl/hetaryl/alkyl benzazole derivatives
concise and direct one-pot [4 + 1] synthetic strategy for the construction of 2-substituted benzazoles such as benzoxazoles and benzothiazoles has been disclosed in high yields (80–98%) by cascade coupling reaction of 2-amino(thio)phenols with β-oxodithioesters. The current approach enables NH/OH/SH functionalization in one-pot under solventless condition leading to diverse benzazoles without use of any
通过2-氨基(硫代)的级联偶联反应,已公开了一种高产率(80-98%)的简洁,直接的一锅[4 +1]合成策略,用于构建2-取代的苯并唑,如苯并恶唑和苯并噻唑酚与β-氧二硫代酯。目前的方法可以在无溶剂条件下在一锅中实现N H / O H / S H官能化,从而无需使用任何外部金属即可产生多种苯并恶唑。各种各样的2-氨基(硫代)酚和β-氧二硫代酯均具有出色的官能团耐受性,可用于该转化。此外,我们通过证明其与DNA拓扑异构酶II抑制剂的多样化多样化的相容性,抢占了这一新策略的广泛含义。
Applying green and highly efficient approach for a facile synthesis of new thiazoloquinoline, thiazolopyridine, and thiazolonaphthyridine derivatives
作者:Zahra Arabpoor、Hamid Reza Shaterian
DOI:10.1007/s13738-018-01579-x
日期:2019.5
AbstractAn eco-friendly approach for the synthesis of new thiazoloquinolines, thiazolopyridines, and thiazolonaphthyridines scaffolds has been achieved using α-enolicdithioesters, cysteamine, arylglyoxal monohydrate, and cyclic 1,3-diketones (dimedone, 4-hydroxycoumarin, and 4-hydroxy-1-methyl-2(1H)-quinolone) under thermal solvent-free conditions. The highlight of this protocol is the generation of
Highly Regioselective One-Pot, Three-Component Synthesis of 1-Aryl-3,4-Substituted/Annulated-5-(Cycloamino)/(Alkylamino)pyrazoles from β-Oxodithioesters
作者:Ganesh C. Nandi、Maya S. Singh、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1002/ejoc.201101397
日期:2012.2
An efficient, highlyregioselective protocol for the synthesis of the title compounds is reported. The reaction involves a one-pot, three-component cyclocondensation of β-oxodithioester, amine, and hydrazine in ethanol at reflux in the presence of a catalytic amount of acetic acid. Densely functionalized pyrazoles were constructed through the cyclization of a thioamide intermediate generated in situ
Access to Fully Substituted Thiazoles and 2,3-Dihydrothiazoles via Copper-Catalyzed [4 + 1] Heterocyclization of α-(<i>N</i>-Hydroxy/aryl)imino-β-oxodithioesters with α-Diazocarbonyls
An efficient chemoselective practical route to fully substituted thiazoles and 2,3-dihydrothiazoles has been devised by [4 + 1] heterocyclization of α-(N-hydroxy/aryl)imino-β-oxodithioesters with in situ generated Cu-carbenoids of diazocarbonyls. The α-(N-hydroxy/aryl)imino-β-oxodithioesters are readily accessible by the reaction of β-oxodithioesters with nitrous acid/nitrosoarenes. The overall transformation