α-Oxoketene Dithioacetals Mediated Benzoannelation of Aromatic Heterocycles: an Efficient Regiocontrolled Synthesis of Highly Substituted and Polycyclic Benzo[b]thiophenes
作者:J.R. Suresh、Okram Barun、H. Ila、H. Junjappa
DOI:10.1016/s0040-4020(00)00722-5
日期:2000.10
An efficient regiocontrolled synthesis of highly substituted and complex polycyclic benzo[b]thiophenes has been developed via our benzoannelation strategy involving conjugate addition–displacement on a variety of α-oxoketenedithioacetals by carbanions derived from 2- and 3-cyanomethylthiophenes followed by acid induced cyclization of the resulting conjugate adducts.
通过我们的苯甲酰化策略,开发了一种高效的区域控制的合成方法,该方法可控制区域取代基和复杂的多环苯并[ b ]噻吩,包括通过2-和3-氰基甲基噻吩的碳负离子在各种α-氧杂环丁烯二硫缩醛上进行共轭加成-置换,然后进行酸诱导的环化反应生成的共轭加合物。
An Expedient New Synthesis of Substituted Carbazoles via α-Oxoketene Acetals through Heteroaromatic Annelation Methodology
Cyclocondensation of α-Oxoketene<i>N,S</i>-Acetals with β-Lithioamino-β-Substituted Acrylonitriles: A Facile Route to 2,6-Substituted 4-Amino-3-cyanopyridines
A novel synthesis of a variety of 2,6-substituted and 3-cyano-4-dialkylamino-2,6-diheteroarylpyridines (4-dialkylamino≡pyrrolidin-1-yl, piperidino, morpholino, diethylamino and N-methylanilino; 6-heteroaryl≡phenyl, anisyl, 2-thienyl; 2-heteroaryl≡methyl, phenyl, 2-furyl and 2-thienyl) has been developed by the reaction of α-oxoketene N,S-acetals 1 with β-substituted β-lithioaminoacrylonitriles 2, generated in situ by either self condensation of lithioacetonitrile or by its reaction with substituted acetonitriles.
Cycloaromatization of Methyl (E)-4-(Methyllithio)-3-(1-pyrrolidinyl)-2-butenoate with α-Oxoketene N,S-Acetals: Direct Synthesis of 3,5-Bis(cycloalkylamino)biphenyls
作者:Kethiri R. Reddy、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1055/s-1995-4029
日期:1995.8
The vinyl carbanion 2 undergoes cycloaromatization with α-oxoketene N,S-acetals 3 through 1,4-conjugate addition-elimination process to afford 3,5-diaminobiphenyls 4 in good yields.
A new general regiocontrolled synthesis of highly substituted and condensed indoles via heteroaromatic annelation
作者:J.R. Suresh、Pranab K. Patra、H. Ila、H. Junjappa
DOI:10.1016/s0040-4020(97)00985-x
日期:1997.10
A new general method for the synthesis of substituted and condensed indoles has been developed via heteroaromatic annelation involving base induced conjugate addition-elimination of 1-methylpyrrole-2-acetonitrile to various α-oxoketene acetals followed by cyclization of the resulting adducts in the presence of TsOH in refluxing benzene.