𝔖 Bobbio Scriptorium
✦   LIBER   ✦

1,4-Dipolar cycloadditions as trapping reactions for zwitterionic intermediates of 2 + 2 cycloadditions

✍ Scribed by Schug, Reinhard; Huisgen, Rolf

Book ID
121291706
Publisher
The Royal Society of Chemistry
Year
1975
Tongue
English
Weight
142 KB
Volume
2
Category
Article
ISSN
0022-4936

No coin nor oath required. For personal study only.

📜 SIMILAR VOLUMES

Zwitterions as Intermediates in 1,3-Dipo
Zwitterions as Intermediates in 1,3-Dipolar Cycloadditions of Electrophilic Azides to 2-Alkylidenetetrahydroimidazoles and 2-Alkylidenedihydrobenzimidazoles
✍ Quast, Helmut ;Ach, Manfred ;Ivanova, Svetlana ;Peters, Eva-Maria ;Peters, Karl 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 736 KB

## Abstract Cyclic ketene __N,N__‐acetals derived from imidazolidine (4a, c) and 2,3‐dihydrobenzimidazole (6a–c) add methanesulphonyl azide (2a) or picryl azide (2f) to afford the zwitterions 5 and 7, respectively. The structure of 7d is elucidated by X‐ray crystallography. Reversibility of formati

Cycloadditions of Aryl-Substituted 1,2,4
Cycloadditions of Aryl-Substituted 1,2,4-Triazines with 2-Cyclopropylidene-1,3-dimethylimidazolidine – Zwitterions as Discrete Intermediates
✍ Michael Ernd; Manfred Heuschmann; Hendrik Zipse 📂 Article 📅 2005 🏛 John Wiley and Sons 🌐 German ⚖ 396 KB

## Abstract Cycloadditions of 2‐cyclopropylidene‐1,3‐dimethylimidazolidine (**1**), a strong, electron‐rich C‐nucleophile, with a variety of aryl‐substituted 1,2,4‐triazines occur at temperatures between −100 and +100°, depending on the substitution pattern. At low temperatures, zwitterions, formed