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1.
A practical and efficient synthesis of methyl 6,7,8,9-tetrahydropyrido[1,2-a]indol-10-ylacetate derivatives 6 is reported. This synthetic approach featured the nucleophilic aromatic substitution of 2-piperidinemethanol derivatives 2 with aryl fluorides 1, and the intramolecular Heck coupling as key steps to afford the desired N-fused tricyclic indoles 6. 相似文献
2.
George Bratulescu 《Tetrahedron letters》2008,49(6):984-986
The synthesis of indoles is accomplished in high yields from phenylhydrazines and pyruvic acid using microwave irradiation. 相似文献
3.
Sheng-Yan Zhang Shan-Gang Sun Yu-Shuang Guo Xiao-Fan Lu Dian-Shun Guo 《Tetrahedron letters》2018,59(41):3719-3723
A highly efficient method for the synthesis of indoles has been successfully developed via a CuMgAl-LDH-catalyzed intramolecular annulation reaction of 2-alkynylsulfonanilides. This CuMgAl-LDH catalyst features facile preparation, recovery, and reuse at least seven times without a marked loss in the catalytic activity, as well as the unique dual activation. Moreover, the crystal structures and Hirshfeld surface analysis of typical indole compounds were also presented. 相似文献
4.
A novel and effective method has been developed for the synthesis of 9H-pyrrolo[1,2-a]indoles by treatment of 3-substituted-4,6-dimethoxyindoles with chalcones in the presence of hydrochloric acid. 相似文献
5.
A general, efficient, and inexpensive method for the N-arylation of indoles using a catalytic system derived from CuI and benzotriazole is reported. Selective mono N-arylation of indoles with ortho-dihaloarenes has also been successfully achieved in good yields using this protocol. 相似文献
6.
Mild and efficient cyclization reaction of 2-ethynylaniline derivatives to indoles in aqueous medium
Results of the optimized cyclization reaction of 2-ethynylaniline derivatives to indoles catalyzed by copper(II) salts are described. The reactions can be carried out in a mixture of H2O and MeOH in the presence of 1-ethylpiperidine at room temperature. These conditions can be applied to a bulky substrate, which is difficult to be cyclized efficiently by existing reaction conditions. Furthermore, this reaction condition was applied to a catalyst recycling reaction system. 相似文献
7.
An efficient difluorohydroxylation of indoles using selectfluor as a fluorinating reagent 总被引:1,自引:0,他引:1
An efficient difluorohydroxylation of substituted indoles leading to 3,3-difluoroindolin-2-ols with good yields by using Selectfluor as the electrophilic fluorinating reagent has been developed. In this methodology, the indole rings were difluorinated highly regioselectively at the C3 carbon site. This protocol is practically convenient, easily handled under mild conditions, and provides an efficient way to produce the unique difluorinated indolin-2-ol structure. When alcohols were used as the nucleophiles instead of H(2)O, the corresponding products were obtained in moderate yields. Based on the experimental observations, a plausible mechanism is proposed. 相似文献
8.
Yu Chen 《Tetrahedron》2009,65(44):8908-8915
A microwave-assisted, one-pot, three-component coupling reaction for the synthesis of indoles has been developed. The reaction is carried out in two steps under standard Sonogashira coupling conditions from an N-substituted/N,N-disubstituted 2-iodoaniline and a terminal alkyne, followed by the addition of acetonitrile and an aryl iodide. A variety of polysubstituted indoles have been prepared in moderate to excellent yields using the present method. 相似文献
9.
Anhydrous ZnCl2 mediated convenient, one-pot synthesis of 3-arylmethyl and diarylmethyl indoles was accomplished in good yields. Under reaction condition, in situ formation of kinetically stable bis(indolyl)methane product was identified. Its subsequent conversion to the thermodynamically stable 3-diarylmethyl indole at elevated temperature and pressure was confirmed by carrying out pressure tube reaction with bis(indolyl)methane. 相似文献
10.
Bimal K. Banik 《Tetrahedron letters》2005,46(14):2479-2482
Michael reaction of indoles with unsaturated ketones has been accomplished in the presence of catalytic amount of iodine under solvent-free condition. 相似文献
11.
Kentaro Okuma Jun-ichi Seto Ken-ichi Sakaguchi Saori Ozaki Noriyoshi Nagahora Kosei Shioji 《Tetrahedron letters》2009,50(24):2943-1400
Reaction of 2-phenylethynyl N-tosylanilide prepared by Pd-free procedure with ZnBr2 (3 equiv) in refluxing toluene gave N-tosyl-2-phenylindole in 93% yield. Treatment of 2-phenylethynylaniline with ZnBr2 (1 equiv) in refluxing toluene resulted in the formation of 2-phenylindole in 91% yield. Catalytic ZnBr2 (0.05 equiv) effectively reacted with 2-alkynylanilines to afford 2-substituted indoles in high yields. Thus, complete Pd-free zinc catalyzed hydroamination of 2-alkynylanilines was achieved. 相似文献
12.
Qiujian Xie Yumin Yang Weijie Zhang Zhu Gao Xiaofeng Li Juntao Tang Chunyue Pan Guipeng Yu 《Chemical science》2021,12(15):5631
Conjugated microporous polymers (CMPs) are cost-effective photocatalysts in organic transformations, while they are usually limited by the insufficient separation of photogenerated charges. Here we report a polarization strategy through molecular geometry optimization to promote the charge separation of CMPs. Three CMP photocatalysts with an alternative donor–acceptor skeleton and tunable symmetry were synthesized by the oxidative coupling of bis-carbazoles with electron-deficient bridges (benzene/pyridine/pyrimidine). Simply regulating the polarization of the starting monomers leads to tailorable porosity, photoelectric properties, and photocatalytic activity of the CMPs. They exhibited high efficiency in C-3 selenocyanation of indoles under visible-light and at room temperature, and pyridine-based CMPs with the largest dipole moment gave a yield of up to 94%, superior to their state-of-the-art photocatalyst counterparts. Photo-physical experiments combined with theoretical calculations further supported that the incorporation of the polarized linker introduced an internal electric field, benefitting efficient charge separation. This offered new insight into developing high-performance photocatalysts.An internal electric field was used to promote the charge separation of conjugated microporous polymers (CMPs). Those with the largest dipole moment exhibited high efficiency in C-3 selenocyanation of indoles under visible-light and room temperature. 相似文献
13.
Yasumitsu Tamura Sundo Kwon Moon Woo Chun Masazumi Ikeda 《Journal of heterocyclic chemistry》1978,15(3):425-427
Treatment of indole, 2-phenylindole, 2-methylindole, and ethyl indole-2-carboxylate with thiocyanogen in acetic acid at 0° afforded the corresponding 3-thiocyanatoindoles in quantitative yields, whereas similar treatment of 3-methyl-2-phenylindoles and 2,3-diphenylindoles gave the corresponding 6-thiocyanatoindoles in high yields. 相似文献
14.
Takayoshi HaraKohsuke Mori Tomoo MizugakiKohki Ebitani Kiyotomi Kaneda 《Tetrahedron letters》2003,44(33):6207-6210
A hydroxyapatite-bound palladium catalyst was found to be effective for the dehydrogenation of various types of indolines to give the corresponding indoles. Moreover, the catalyst was readily recovered from the reaction mixture, and could be reused without any loss of its catalytic activity. 相似文献
15.
[reaction: see text] The reaction of a variety of indoles with N-thioalkyl- and N-thioarylphthalimides to produce 3-thioindoles is reported. Catalytic quantities of halide-containing salts are crucial to the success of this reaction. This highly efficient reaction provides sulfenylated indoles from bench-stable, readily available starting materials in good to excellent yields. 相似文献
16.
Mukund G. Kulkarni Sanjay W. Chavhan Mayur P. Desai Yunnus B. Shaikh Dnyaneshwar D. Gaikwad Attrimuni P. Dhondge Ajit S. Borhade Vijay B. Ningdale Deekshaputra R. Birhade Nagorao R. Dhatrak 《Tetrahedron letters》2010,51(34):4494-6381
Application of Wittig olefination-Claisen rearrangement protocol for the short synthesis of furo[2,3-b]indoles is described. 相似文献
17.
Daohong Yu Wai-Pong To Yungen Liu Liang-Liang Wu Tingjie You Jesse Ling Chi-Ming Che 《Chemical science》2021,12(42):14050
The photo-induced cleavage of C(sp2)–Cl bonds is an appealing synthetic tool in organic synthesis, but usually requires the use of high UV light, photocatalysts and/or photosensitizers. Herein is described a direct photo-induced chloroarene activation with UVA/blue LEDs that can be used in the reductive Heck cyclization of indoles and without the use of a photocatalyst or photosensitizer. The indole compounds examined display room-temperature phosphorescence. The photochemical reaction tolerates a panel of functional groups including esters, alcohols, amides, cyano and alkenes (27 examples, 50–88% yields), and can be used to prepare polycyclic compounds and perform the functionalization of natural product analogues in moderate to good yields. Mechanistic experiments, including time-resolved absorption spectroscopy, are supportive of photo-induced electron transfer between the indole substrate and DIPEA, with the formation of radical intermediates in the photo-induced dearomatization reaction.Metal- and photocatalyst-free reductive Heck cyclization of indoles under light irradiation was developed and used to prepare polycyclic compounds and functionalize natural product analogues in moderate to good yields. 相似文献
18.
Cai Chen Huan-Xi Feng Zhi-Long Li Pin-Wen Cai Yan-Kai Liu Lian-Hai Shan Xian-Li Zhou 《Tetrahedron letters》2014
A highly efficient route to C-3 alkyl-substituted indoles via completely metal-free catalytic transfer hydrogenation of 3-indolemethanols was developed. This process proceeds via vinylogous iminium intermediates formed in situ in the presence of Brønsted acids, and Hantzsch ester is used as the reductant. The reduction works extremely well with a large substrate scope, and the yields exceed 90% in almost all cases. 相似文献
19.
20.
A simple, efficient, and inexpensive copper catalyzed protocol has been developed for cross-coupling of indoles with aryl halides by using glycerol as a green recyclable solvent and DMSO as an additive. The reaction was carried out at low catalyst loading furnishing various N-aryl indoles in good to excellent yield. This copper/glycerol mixture was recycled up to four runs without any loss in its catalytic activity. 相似文献