scholarly journals Activated lactams. VI. The cycloaddition reaction of cyclic ketene-S,N-acetals with dimethyl acetylenedicarboxylate.

1982 ◽  
Vol 30 (11) ◽  
pp. 3959-3964 ◽  
Author(s):  
HIROKI TAKAHATA ◽  
AKIRA TOMIGUCHI ◽  
ATSUSHI HAGIWARA ◽  
TAKAO YAMAZAKI
Keyword(s):  
Cycloaddition Reaction ◽  
Dimethyl Acetylenedicarboxylate

1,3-Dipolar Cycloaddition Reaction of Dimethyl Acetylenedicarboxylate with Hydrazones

Heterocycles ◽  
1974 ◽  
Vol 2 (2) ◽  
pp. 280 ◽  
Author(s):  
Haruo Ogura ◽  
Hiroshi Takahashi ◽  
Kazuo Kubo ◽  
Kozo Ogawa ◽  
Hitomi Sakai
Keyword(s):  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate

scholarly journals Huisgen [3 + 2] Dipolar Cycloadditions of Phthalazinium Ylides to Activated Symmetric and Non-Symmetric Alkynes

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4416
Author(s):  
Vasilichia Antoci ◽  
Costel Moldoveanu ◽  
Ramona Danac ◽  
Violeta Mangalagiu ◽  
Gheorghita Zbancioc
Keyword(s):  
Reaction Time ◽  
Comparative Study ◽  
Cycloaddition Reaction ◽  
Environmentally Friendly ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
Thermal Heating ◽  
Dipolar Cycloadditions ◽  
Methyl Propiolate

We present herein a straightforward and efficient pathway for the synthesis of pyrrolophthalazine cycloadducts via Huisgen [3 + 2] dipolar cycloaddition reactions of phthalazinium ylides to methyl propiolate or dimethyl acetylenedicarboxylate (DMAD). A thoroughly comparative study concerning the efficiency of synthesis, conventional thermal heating (TH) versus microwave (MW) and ultrasound (US) irradiation, has been performed. The cycloaddition reactions of phthalazinium ylides to methyl propiolate occur regiospecific, with a single regioisomer being obtained. Under conventional TH, the cycloaddition reaction of phthalazinium ylides with DMAD occurs to a mixture of inseparable partial and fully aromatized pyrrolophthalazine cycloadducts, while MW or US irradiation are leading only to fully aromatized compounds, with the reactions becoming selective. A feasible mechanism for formation of fully aromatized compounds is presented. Besides selectivity, it has to be noticed that the reaction setup under MW or US irradiation offer a number of other certain advantages: higher yields, decreasing of the amount of used solvent comparative with TH, decreasing of the reaction time from hours to minutes and decreasing of the consumed energy; consequently, these reactions could be considered environmentally friendly.

scholarly journals An electron localization function analysis of the molecular mechanism and the C–O bond formation in the [3+2] cycloaddition reaction involving zwitterionic type between a nitrone and an electron deficient ethyne

2019 ◽  
Vol 45 ◽  
pp. 146867831982574
Author(s):  
Abdelilah Benallou ◽  
Habib El Alaoui El Abdallaoui ◽  
Hocine Garmes
Keyword(s):  
Electron Density ◽  
Function Analysis ◽  
Bond Formation ◽  
Cycloaddition Reaction ◽  
Intrinsic Reaction Coordinate ◽  
Dimethyl Acetylenedicarboxylate ◽  
Central Carbon ◽  
One Step ◽  
Free Activation Energy ◽  
Step Mechanism

The mechanistic nature of a [3+2] cycloaddition reaction involving zwitterionic species has been investigated, and the changes of electron density related to the O–C and C–C bond formation along the intrinsic reaction coordinate have been characterized. This polar [3+2] cycloaddition reaction, which takes place through a non-concerted two-stage one-step mechanism, proceeds with a moderate Gibbs free activation energy of 21 kcal mol−1. The reaction begins by the creation of a pseudoradical centre at the central carbon, first on the dimethyl acetylenedicarboxylate, and second on the nitrone framework. This immediately favours the formation of the first O–C single bond by donation of some electron density of the oxygen atom lone pairs, which represents the most attractive centre in this cycloaddition reaction.

An unexpected [2+2]-cycloaddition reaction of 4-methyldithieno-[3,4-b:3′,2′-d]pyridinium iodide with dimethyl acetylenedicarboxylate

Tetrahedron ◽  
1995 ◽  
Vol 51 (48) ◽  
pp. 13185-13196 ◽  
Author(s):  
Ecaterina Temciuc ◽  
Anna-Britta Hornfeldt ◽  
Salo Gronowitz ◽  
Claes Stlhandske
Keyword(s):  
Cycloaddition Reaction ◽  
Dimethyl Acetylenedicarboxylate
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