Recent advances in the synthesis of indole embedded heterocycles with 3-diazoindolin-2-imines.

Author(s):  
Muhammad Suleman ◽  
Ping Lu ◽  
Yanguang Wang

Indole embedded α-diazo amidines (i.e. 3-diazoindolin-2-imines) are important additions to the cyclic diazo compound family. The ease of their preparation, typical reactivity as diazo compounds, successful generation of Rh, Cu,...

1966 ◽  
Vol 44 (9) ◽  
pp. 1075-1081 ◽  
Author(s):  
N. Latif ◽  
I. Fathy

The benzoxanthene ethers Ia–IIb are obtained in good yields by the action of tetrachloro-and tetrabromo-o-benzoquiuone on 1,2- and 3,4-benzoxanthione, respectively. The benzopyran analogues IIIa–IIIb are obtained by the interaction of the corresponding haloquinone and coumarin hydrazone. The latter, which is now readily obtained by the action of hydrazine hydrate on coumarin-2-thione, condenses with thioketones to give coumarin azines. The benzopyran ethers IIIa and IIIb are cleaved by malononitrile, cyanoacetic ester, hydrazine hydrate, phenylhydrazine, and benzoylhydrazine, yielding the unsaturated nitriles (Va–Vb) and the corresponding hydrazones, respectively.1,2-Benzoxanthione reacts with 9-diazoxanthene, diphenyldiazomethane, and diphenylenediazomethane to give the ethylene sulfides VI–VIII, respectively. However, coumarin-2-thione reacts with the diazo compounds in a different manner; it gives the ethylenes X and XI directly, together with the symmetrical thiiranes XII and XIII, in the cases of diphenyldiazomethane and 9-diazoxanthene, respectively, whereas the cyclopropane derivative XIV is produced in the case of diphenylenediazomethane. XIV is also obtained by the photochemical interaction of coumarin itself and the diazo compound.


Author(s):  
Il'ya I. Ustinov ◽  
Nikolay V. Khlytin ◽  
Igor' V. Blokhin ◽  
Irina V. Shakhkel'dyan ◽  
Yuriy M. Atroshchenko ◽  
...  

Interaction between 5,7-dinitro-8-hydroxyquinoline hydride anionic σ-adduct and chlorides of substituted aryldiazonium in water yielded 5-arylazo-7-nitro-8-hydroxyquinolines, the substitution products of the nitro group at the C-5 σ-adduct position. The direction of the reaction agrees with the quantum-chemical calculations carried out earlier and the GMLA principle, which assumes that the mild acid, which is a diazocathione, will attack the reaction center to which the softest base corresponds, that is, the least negatively charged C-5 carbon atom, in contrast to the C-7 atom. It is shown that the yield of the product increases with the presence of an electron-withdrawing substituent in the diazocomponent. Also in this study, the synthesis of the hydride σ-adduct of 5,7-dinitro-8-hydroxyquinoline was optimized. It was found that the use of pure dimethylacetamide as a solvent, as well as the addition of sodium carbonate, increases the yield and purity of the synthesized σ-adduct. The structure of the obtained compounds was proved by the methods of NMR and IR spectroscopy. In the IR spectra of all synthesized azo compounds, weak absorption bands corresponding to the stretching vibrations of the azogroup (N = N) are fixed in the range of 1400-1465 cm-1, which also indirectly confirms the expected direction of the reaction. Otherwise, the bands of the azogroup vibrations would be shifted to the 1500-1600 cm-1 region as a result of azo-hydrazoic tautomerism. In 1H NMR spectra of synthesized compounds, there is no proton signal of intramolecular hydrogen bond at δ 14-15 ppm, characteristic of the hydrazine form. The proton signals of the arylazo group also confirm the presence of the latter. The use of anionic hydride σ-complexes of dinitroquinoline derivatives as azo-component in the reaction with aromatic diazo compound expands the synthetic possibilities of the azo coupling reaction and allows to obtaine new nitroazoquinolines.


2019 ◽  
Author(s):  
Masaaki Komatsuda ◽  
Hiroki Kato ◽  
Kei Muto ◽  
Junichiro Yamaguchi

Acatalytic dearomative three-component reaction of bromoarenes with TMS-diazomethane and allyl borate was developed. The key of this assembling reaction is the use of a diazo compound to generate a Pd-π-benzyl intermediate through a Pd-carbenoid species. This method allowed for a dearomative functionalization using arenes as limiting reagents. Heteroaryl bromides were also applicable to give dearomatized structures under the reaction conditions.


2010 ◽  
Vol 8 (1) ◽  
pp. 223-228 ◽  
Author(s):  
Zhenfeng Liu ◽  
Jianyong Liu

AbstractThe mechanism of the dirhodium tetracarboxylate-catalyzed O-H insertion reaction of diazomethane and methyl diazoacetate with H2O has been studied in detail using DFT calculations. The rhodium catalyst and a diazo compound couple to form a rhodiumcarbene complex. Of two reaction pathways of the Rh(II)-carbene complex with H2O, the stepwise pathway is more preferable than the concerted one. Formation of a Rh(II) complex-associated oxonium ylide is an exothermal process, and direct decomposition of the ylide gives a very high barrier. The high barriers for the 1,2-H shift of Rh(II) complex-associated oxonium ylides make the ylides become stable intermediates in both reactions, especially for the reactions in solution. Difficulty in formation of a free oxonium ylide supports experimental results, indicating that the Rh(II) complex-catalyzed nucleophilic addition of a diazo compound proceeds via a Rh(II) complex-associated oxonium ylide rather than via a free oxonium ylide.


Synthesis ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 79-94
Author(s):  
Thierry Ollevier ◽  
Virginie Carreras ◽  
Nour Tanbouza

AbstractThe use of iron catalysis to enable reactions with diazo compounds has emerged as a valuable tool to forge carbon–carbon or carbon–heteroatom bonds. While diazo compounds are often encountered with toxic and expensive metal catalysts, such as Rh, Ru, Pd, Ir, and Cu, a resurgence of Fe catalysis has been observed. This short review will showcase and highlight the recent advances in iron-mediated reactions of diazo compounds.1 Introduction2 Insertion Reactions2.1 Insertion into B–H Bonds2.2 Insertion into Si–H Bonds2.3 Insertion into N–H Bonds2.4 Insertion into S–H bonds3 Ylide Formation and Subsequent Reactions3.1 Doyle–Kirmse Rearrangement3.2 [1,2]-Stevens and Sommelet–Hauser Rearrangements3.3 Olefination Reactions3.4 Cycloaddition Reactions3.5 gem-Difluoroalkenylation4 Three-Component Reactions5 Miscellaneous6 Conclusion


Synthesis ◽  
2020 ◽  
Author(s):  
Shiyong Peng ◽  
Nuan Chen ◽  
Min He ◽  
Ting Zhou ◽  
Yuqi Zhu ◽  
...  

AbstractThis short review summarizes the most recent developments (since 2010) in the tandem cyclization/cycloaddition of allene intermediates­, generated from the copper-catalyzed cross-coupling of diazo compounds with terminal alkynes, to afford cyclic compounds.1 Introduction2 Cyclization2.1 Cyclization with Nucleophiles2.2 Cyclization with Electrophiles2.3 6π-Electrocyclization2.4 Other Cyclization3 Cycloaddition4 Conclusion


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1339
Author(s):  
Rui Zhang ◽  
Huaiwei Ding ◽  
Xiangling Pu ◽  
Zhiping Qian ◽  
Yan Xiao

The construction of a C-S bond is a powerful strategy for the synthesis of sulfur containing compounds including sulfides, sulfoxides, and sulfones. Recent methodological developments have revealed lots of novel protocols for C-S bond formation, providing easy access to sulfur containing compounds. Unlike traditional Ullmann typed C-S coupling reaction, the recently developed reactions frequently use non-halide compounds, such as diazo compounds and simple arenes/alkanes instead of aryl halides as substrates. On the other hand, novel C-S coupling reaction pathways involving thiyl radicals have emerged as an important strategy to construct C-S bonds. In this review, we focus on the recent advances on the synthesis of sulfides, sulfoxides, and sulfones from non-halide substrates involving C-S bond construction.


2015 ◽  
Vol 6 (1) ◽  
pp. 752-755 ◽  
Author(s):  
Nicholas A. McGrath ◽  
Kristen A. Andersen ◽  
Amy K. F. Davis ◽  
Jo E. Lomax ◽  
Ronald T. Raines

A diazo compound is shown to convert carboxylic acids to esters efficiently in an aqueous environment.


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