Thermal [4p+2p]-Type Cycloaddition Reactions of Pyrrole Derivatives with 3-Cyanocyclopropene Generated in situ

Heterocycles ◽  
1989 ◽  
Vol 29 (11) ◽  
pp. 2135 ◽  
Author(s):  
Katsuhiro Saito ◽  
Kazuaki Ito ◽  
Kensuke Takahashi
Keyword(s):  
Cycloaddition Reactions ◽  
Pyrrole Derivatives

In Situ Generation of Unstable Difluoromethylphosphonate-Containing Diazoalkanes and Their Use in [3 + 2] Cycloaddition Reactions with Vinyl Sulfones

2021 ◽  
Vol 23 (3) ◽  
pp. 1130-1134
Author(s):  
Haibo Mei ◽  
Li Wang ◽  
Romana Pajkert ◽  
Qian Wang ◽  
Jingcheng Xu ◽  
...  
Keyword(s):  
Cycloaddition Reactions ◽  
In Situ Generation

Symmetrical tetra-β″-sulfoleno-meso-aryl-porphyrins — synthesis, spectroscopy and structural characterization

2014 ◽  
Vol 18 (01n02) ◽  
pp. 115-122 ◽  
Author(s):  
Srinivas Banala ◽  
Klaus Wurst ◽  
Bernhard Kräutler
Keyword(s):  
Metal Complexes ◽  
Crystal Structures ◽  
Structural Characterization ◽  
Building Blocks ◽  
Cycloaddition Reactions ◽  
One Pot

We report here the preparation (in "one-pot") of a tetra-β″-sulfoleno-meso-aryl-porphyrin in about 80% yield by using an optimized modification of Lindsey's variant of the Adler–Longo approach. The Zn ( II )-, Cu ( II )- and Ni ( II )-complexes of the symmetrical porphyrin were prepared and characterized spectroscopically. Crystal structures of the fluorescent Zn ( II )- and of the non-fluorescent Ni ( II )-tetra-β″-sulfoleno-meso-aryl-porphyrinates showed the highly substituted porphyrin ligands to be nearly perfectly planar. The Zn ( II )-complex of this porphyrin has been used as a thermal precursor of a reactive diene, and — formally — of lateral and diagonal bis-dienes, of a tris-diene and of a tetra-diene, which all underwent [4 + 2]-cycloaddition reactions in situ with a range of dienophiles. Thus, the tetra-β″-sulfoleno-meso-aryl-porphyrin and its metal complexes represent reactive building blocks, "programmed" for the syntheses of symmetrical and highly functionalized porphyrins.

Recent Advances of 1,3,5-Triazinanes in Aminomethylation and Cycloaddition Reactions

Synthesis ◽  
2020 ◽  
Vol 52 (17) ◽  
pp. 2469-2482
Author(s):  
Jia-Rong Chen ◽  
Dong Liang ◽  
Wen-Jing Xiao
Keyword(s):  
Reaction Mechanisms ◽  
Short Review ◽  
Cycloaddition Reactions ◽  
Recent Advances ◽  
Nitrogen Containing Compounds

1,3,5-Trisubstituted 1,3,5-triazinanes (hexahydro-1,3,5-triazines), as stable and readily available surrogates for formaldimines, have found extensive applications for the construction of various nitrogen-containing compounds. The formaldimines, formed in situ from this reagent class, can participate in various aminomethylation and cycloaddition­ reactions. This short review presents recent advances in this field with emphasis on the conceptual ideas behind the developed methodologies and the reaction mechanisms.1 Introduction2 Aminomethylations with 1,3,5-Triazinanes3 Cycloadditions with 1,3,5-Triazinanes3.1 Use of 1,3,5-Triazinanes as Two-Atom Synthons3.2 Use of 1,3,5-Triazinanes as Three-Atom Synthons3.3 Use of 1,3,5-Triazinanes as Four-Atom Synthons3.4 Use of 1,3,5-Triazinanes as Six-Atom Synthons4 Conclusions

Synthesis of Oxazoline and Oxazole Derivatives by Hypervalent-Iodine-Mediated Oxidative Cycloaddition Reactions

Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2299-2310 ◽  
Author(s):  
Akira Yoshimura ◽  
Akio Saito ◽  
Viktor V. Zhdankin ◽  
Mekhman S. Yusubov
Keyword(s):  
Heterocyclic Compounds ◽  
Short Review ◽  
Active Species ◽  
Hypervalent Iodine ◽  
Cycloaddition Reactions ◽  
Iodine Species ◽  
Oxazole Derivatives

Organohypervalent iodine reagents are widely used for the preparation of various oxazolines, oxazoles, isoxazolines, and isoxazoles. In the formation of these heterocyclic compounds, hypervalent iodine species can serve as the activating reagents for various substrates, as well as the heteroatom donor reagents. In recent research, both chemical and electrochemical approaches toward generation of hypervalent iodine species have been utilized. The in situ generated active species can react with appropriate substrates to give the corresponding heterocyclic products. In this short review, we summarize the hypervalent-iodine­-mediated preparation of oxazolines, oxazoles, isoxazolines, and isoxazoles starting from various substrates.1 Introduction2 Synthesis of Oxazolines3 Synthesis of Oxazoles4 Synthesis of Isoxazolines5 Synthesis of Isoxazoles6 Conclusion

[4 + 2]-Cycloaddition Reactions Involving α-Oxo Thioketone Intermediates

2002 ◽  
Vol 57 (8) ◽  
pp. 922-927 ◽  
Author(s):  
Mohamed I. Hegab ◽  
Abd El-Galil A. Amr ◽  
Farouk M. E. Abdel-Megeid
Keyword(s):  
Cycloaddition Reactions ◽  
Iodide Ions ◽  
Sulfenyl Chlorides ◽  
Chalcone Derivative

α-Chloro β-oxo sulfenyl chlorides 2 were reduced by iodide ions to the corresponding α-oxo thioketones 3 which dimerized in situ in a hetero-[4 + 2] cycloaddition to give the 1,3,4- oxadithiin derivatives 4. The α-oxo thioketones 3, in situ, cyclized also with 2,3-dimethyl-1,3- butadiene to give the corresponding adducts 5 and only in case of the oxo thioketone intermediate 3d two products 4d and 5d were obtained. Also, The α-oxo thioketones 3a,c, underwent in situ, cycloaddition with furan to give the corresponding adducts 6a,c together with the corresponding thioketone dimers 4a,c. When this reaction was carried out in the presence of diethyl acetylenedicarboxylate or chalcone derivative 8, only the oxo thioketone dimers 4a-d were obtained.

Palladium-catalyzed one-pot cycloaddition reactions of thioureas with 3H-indol-3-ones generated in situ from 2-alkynyl arylazides: rapid and efficient access to imidazoloindolines

2020 ◽  
Vol 7 (21) ◽  
pp. 3480-3485
Author(s):  
Ping Li ◽  
Boyu Zhu ◽  
Yao Xu ◽  
Zhiqiang Zhou ◽  
Guiwen Hu ◽  
...  
Keyword(s):  
Cycloaddition Reactions ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Efficient Access ◽  
Palladium Catalyzed

An efficient palladium-catalyzed one-pot synthesis of imidazoloindolines from 2-alkynyl arylazides under mild reaction conditions has been described.

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