Chemo- and regioselective synthesis of polysubstituted 2-aminothiophenes by the cyclization of<i>gem</i>-dibromo or<i>gem</i>-dichloroalkenes with β-keto tertiary thioamides
作者:Xuxue Zhang、Chuan Liu、Yupian Deng、Song Cao
DOI:10.1039/d0ob01821j
日期:——
A facile and practical method for the synthesis of 2,3,4-trisubstituted 2-aminothiophenes by the cyclization ofgem-dibromoalkenes orgem-dichloroalkenes with β-keto tertiary thioamides has been developed.
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
Iron-Promoted Domino Annulation of α-Enolic Dithioesters with Ninhydrin under Solvent-Free Conditions: Chemoselective Direct Access to Indeno[1,2-<i>b</i>]thiophenes
An efficient, straightforward, and highly chemoselective strategy has been devised for the synthesis of a broad range of indeno[1,2-b]thiophenes through the annulation of α-enolic dithioesters with ninhydrin undersolvent-freeconditions. The advantages of this nucleophilic domino substitution/cyclization sequence are highlighted by the use of inexpensive and readily available FeCl3·6H2O as the catalyst
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
Synthesis of N,N-disubstituted 2-aminothiophenes by the cyclization of gem-difluoroalkenes with β-keto thioamides
作者:Xuxue Zhang、Mingsheng Wu、Juan Zhang、Song Cao
DOI:10.1039/c7ob00368d
日期:——
gem-difluoroalkenes with β-keto tertiary thioamides is described. The reactions proceed smoothly with the assistance of K2CO3 under transition-metal-free conditions, affording a variety of valuable N,N-disubstituted 2-aminothiophenes in moderate to good yields.
描述了一种新的有效的方法,该方法可通过用β-酮基叔硫酰胺环合宝石-二氟烯烃来构建高度官能化的氨基噻吩。在无过渡金属的条件下,反应在K 2 CO 3的帮助下顺利进行,以中等至良好的收率提供了各种有价值的N,N-二取代的2-氨基噻吩。