Organometallic routes to 2,5-dihydroxy-3-(indol-3-yl)benzoquinones. Synthesis of demethylasterriquinone B4

A method has been developed to sequentially add indole-3-mercurials to dichlorinated quinones using palladium catalysis. These reactions can be used in the modular assembly of bis(indol-3-yl)benzoquinones, a significant natural product family.     

Synthesis of trans-2-(indol-3-yl)-3-nitrothiochroman-4-ones from 3-nitrothiochromone and indoles

1,4-Nucleophilic addition reactions of 3-nitrothiochromone with indoles gave a number of novel trans-2-(indol-3-yl)-3-nitrothiochroman-4-ones in 36–89% yields. During the reactions, the thiopyrone ring underwent no opening.     

Synthesis of 2-alkyl-3-(2-benzoxazolon-3-yl)indoles

It was shown that 3-(2-oxoalkyl)-2-benzoxazolones with phenylhydrazine in the presence of polyphosphoric acid form the corresponding 2-alkyl-3-(2-benzoxazolon-3-yl)-indoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1087, August, 1984.     

Synthesis of 2-(pyrimidin-4-yl)indoles

The synthesis of 2-substituted isomers of the meridianins, a familiy of bioactive indole alkaloids isolated from the tunicate Aplidium meridianum, was undertaken. The synthetic route comprises six steps, with a microwave promoted Fischer cyclization as the key reaction.     

Synthesis of (indol-2-yl)furazans

The Bischler reaction and some its modifications were used for the synthesis of derivatives of (indol-2-yl)furazans starting from 3-bromoacetyl-4-methylfurazan and substituted annilines. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 400–401, February, 1999.     

Acylation of n-phenyl-2-(indol-3-yl)succinimides

Treatment of N-phenyl-2-(1-R-indol-3-yl)succinimides with acetyl perchlorate leads to acylation of the benzene ring of the indole substituent.L. M. Litvinenko Institute of Physico-Organic and Carbon Chemistry, Ukrainian Academy of Sciences, Donetsk 340114. A. N. Kosygin State Textile Academy, Moscow 117918, GSP-1. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 85–88, January, 1997.     

Synthesis of 3-(2-nitroalkyl) indoles by reaction of 3-(1-arylsulfonylalkyl) indoles with nitroalkanes

Sulfonyl indoles act as effective precursors of vinylogous imino derivatives in the reaction with nitroalkanes under basic conditions leading to the corresponding nitro indoles in good yield. This procedure represents an effective option to the classical conjugate addition of indoles to nitroalkenes.     

Quantum chemical study of the transformation of 2-(N-alkylamino)-3-(indol-1-yl)-and 2-(N-alkylamino)-3-(indol-3-yl)maleimides by protic acids: Tandem hydride transfer/cyclization mechanism

The geometric parameters, the charge distribution, and the energetics of N-methyl-2-(N-ethylanilino)-3-(indol-1-yl)-and N-methyl-2-(N-ethylanilino)-3-(indol-3-yl)maleimides and their conjugated acids were studied by density functional theory calculations at the B3LYP/6-31G(d) level. The mechanism of the tandem hydride transfer/cyclization sequence, which occurs after protonation of N-methyl-2-(N-ethylanilino)-3-(indol-1-yl)-and N-methyl-2-(N-ethylanilino)-3-(indol-3-yl)maleimides, was analyzed. The investigation of the potential energy surface for the tandem hydride transfer/cyclization of the iminium cation that formed upon protonation revealed that the hydride transfer followed by intramolecular cyclization at position 7 of the indole fragment in N-methyl-2-(N-ethylanilino)-3-(indol-1-yl)maleimide is the preferable process, unlike alternative intramolecular cyclization involving the cationic center at the C(2) atom of the indole fragment and the benzene ring of the N-ethylaniline fragment of the indoleninium cation in N-methyl-2-(N-ethylanilino)-3-(indol-3-yl)maleimide. A study of the key intermediates of the assumed reaction mechanism demonstrated that these intermediates are actually stationary points on the potential energy surface (minima and transition states). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2069–2073, December, 2006.     

Synthesis of 4-substituted 3-(indol-3-yl)maleimides and azepines with annelated indole and maleimide nuclei

A series of 4-substituted 3-(indole-3-yl)maleimides has been synthesized. Upon the action of CH₃SO₃H in TFA, the 3-(indole-3-yl)-4-(arylalkylamino)-maleimides undergo cyclization to give 12b,13-dihydro-4bH-indolo[3,2-d]pyrrolo[3,4-b][1]benzazepine-5,7(6H,8H)-dione derivatives.     

1-(2-螺二芴)-3,4-二[3-(2,5-二甲基呋喃)-2,5-二氢吡咯的合成及光致变色性质的研究

将螺二芴引入二芳基乙烯分子中,设计合成了一种新型的含螺二芴呋喃芳香杂环的二芳基乙烯光致变色分子7a.用FT-IR,NMR,MS和元素分析进行结构表征;研究了7a在正己烷溶液和乙腈溶液中的光致变色反应,结果表明7a在两种溶剂中均具有良好的光致变色性能.并且7a在正己烷溶液中变色速率和转化率比在乙腈溶液中大.还研究了7a光致变色过程中荧光光谱的变化,发现关环反应后荧光被淬灭,并且7a的荧光发射峰在极性溶剂中有很大的蓝移.研究了开环态7a,关环态7b的热稳定性,发现7a的热失重温度比未用螺二芴修饰的8a提高了100℃.7b的热稳定性也比8b高.     

Synthesis of indolylalkylphosphonates and 3-(1-diphenylphosphinoalkyl) indoles by reaction of 3-(1-arylsulfonylalkyl) indoles with phosphorus derivatives

Dialkyl phosphites as well as diphenylphosphine react with 3-(1-arylsulfonylalkyl) indoles under basic conditions leading to a formal substitution of the arylsulfonyl group through a reactive 3-alkylidene indole intermediate.     

Synthesis of N-(indol-3-yl)-N′,N′-dialkylamidines by the vilsmeier reaction with 3-aminoindoles

3-Aminoindoles substituted at C-2 and C-5 of the indole ring are converted by the action of Vilsmeier complexes into N-(indol-3-yl)-N,N-dialkylamidines. When C-2 is unsubstituted, the formylation proceeds but not the acetylation of this position. N-(Indol-3-yl)-N,N-dimethylacetamidine reacts with the complex obtained from DMF and POCl₃ to give 2-dimethylamino-3-formyl--carboline. The optimal conditions were found for the conversion of amidines to amides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 76–81, January, 1985.     

蒙脱土K10-ZnCl2催化下研磨法合成二吲哚甲烷衍生物

蒙脱土K10固载_^ZnCl2是一个有效的环境友好催化剂. 在蒙脱土K10-ZnCl2催化下, 将吲哚与芳香醛混合在研钵中研磨2～8 min, 可得到收率为66%～97%的二吲哚甲烷衍生物. 该方法具有操作简便、反应条件温和、反应时间缩短、 对环境友好等优点.