Inter- and Intramolecular Cycloaddition Reactions of Ethenetricarboxylates with Styrenes and Halostyrenes

Synthesis ◽  
2020 ◽  
Author(s):  
Shoko Yamazaki ◽  
Zhichao Wang ◽  
Kentaro Iwata ◽  
Khotaro Katayama ◽  
Hirotaka Sugiura ◽  
...  

AbstractInter- and intramolecular cycloaddition reactions of ethenetricarboxylates with styrenes and α-halostyrenes have been investigated. The reactions of ethenetricarboxylates with styrenes or α-bromostyrenes in the presence of SnCl4 or SnBr4 stereoselectively gave 2,4-cis-substituted cyclobutanes. The intramolecular cycloaddition reactions of a series of styrene-functionalized ethenetricarboxylate amides, including in situ generated derivatives, showed high diversity of reaction modes depending on the structures and substituents of the substrates. The regioselectivity and stereoselectivity of the reactions as well as reaction mechanisms were discussed based on the DFT calculations.

Synthesis ◽  
2020 ◽  
Vol 52 (17) ◽  
pp. 2469-2482
Author(s):  
Jia-Rong Chen ◽  
Dong Liang ◽  
Wen-Jing Xiao

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


2007 ◽  
Vol 85 (2) ◽  
pp. 96-104 ◽  
Author(s):  
T Stanley Cameron ◽  
Andreas Decken ◽  
Mary Gabriel ◽  
Carsten Knapp ◽  
Jack Passmore

The stepwise symmetry-allowed cycloaddition reactions of [SNS]+ with the dinitriles NC–X–CN (X = CCl2, CO) were investigated. The reaction of [SNS]+ and dinitrile in 2:1 ratio yielded the dicycloaddition product quantitatively after 2 weeks (in situ 13C NMR). At a 1:1 ratio, mixtures of mono- and dicycloaddition products were obtained that could not be completely separated from one another. The energetics of the reaction were estimated in the gas phase, in solution (SO2 and CH2Cl2), and solid phases using DFT calculations (PBE0/6-311G*) and a "volume-based thermodynamics" approach for lattice enthalpies. Monocycloaddition products are stable in the gas phase and in solution with respect to disproportionation reactions, but in the solid state the disproportionation of 2 [NC–X–(CNSNS)][AsF6] into [X(CNSNS)2][AsF6]2 and NC–X–CN is strongly favored because of the higher lattice enthalpy of the 1:2 salt. In the gas phase, the second cycloaddition is endothermic because of the charge repulsion of the two positive charges, but in the solid state the reaction is strongly favored because of the lattice enthalpy gain on the formation of the 1:2 ([X(CNSNS)2][AsF6]2) from two 1:1 salts ([NC–X–(CNSNS)][AsF6] and [SNS][MF6]). The crystal structures of the dicycloaddition products [Cl2C(CNSNS)2][AsF6]2 and [OC(CNSNS)2][AsF6]2 and the monocycloaddition product [Cl2C(CNSNS)CN][AsF6] were obtained. In [Cl2C(CNSNS)CN][AsF6], the free nitrile groups interact with neighboring heterocycles further demonstrating that potential of free nitrile groups for introducing intermolecular interactions. [OC(CNSNS)2]2+ is a planar dication, which adopts the conformation with Sδ+···Oδ– contacts to optimize intramolecular electrostatic interactions.Key words: crystal structure, sulfur-nitrogen, 1,3,2,4-dithiadiazolyium, nitriles, cycloaddition, DFT calculations, thermodynamics, energetics.


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

Author(s):  
Amun Amri ◽  
Ahmad Ainun Najib ◽  
Monita Olivia ◽  
Mohammednoor Altarawneh ◽  
Aman Syam ◽  
...  

2001 ◽  
Vol 11 (1) ◽  
pp. 19-20 ◽  
Author(s):  
Nataliya N. Mochulskaya ◽  
Anatoly A. Andreiko ◽  
Valery N. Charushin ◽  
Boris V. Shulgin ◽  
Dmitry V. Raikov ◽  
...  

2014 ◽  
Vol 18 (01n02) ◽  
pp. 115-122 ◽  
Author(s):  
Srinivas Banala ◽  
Klaus Wurst ◽  
Bernhard Kräutler

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.


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