1,3-Bis(dimethylamino)vinylcarben

Abstract

die mit Dimethylamin die Furane ( 2 2 a ) (49 %, orangegelbes 01) und ( 2 2 b ) (36 %, orangerotes 01) bilden. HBF4 wandelt ( 2 2 ) wieder in ( 2 3 ) um. -Funfringe anstelle von (9) erhalt man auch, wenn man ( 8 b ) und ( 8 k ) mit uberschussigem Dimethylamin behandelt: ( 2 4 ) (72 %) und ( 2 5 ) sind Verbindungen, die sich als Vorstufen fur die Gewinnung donorsubstituierter Cyclopentadienyliumsalze und Cyclopentadienone anbieten. L J Schema 4. Cyclische Reaktionsprodukte der Verbindungen (6) und (8).

The Versatility of Pentalene Coordination to Transition Metals: A Density Functional Theory Investigation

“…These compounds form on deprotonation of the corresponding salts or by reduction of thiones with potassium. Very few reports, however, have appeared dealing with the decarboxylation of pseudo‐cross‐conjugated heterocyclic mesomeric betaines 14–16. Some very interesting reports of the reverse process deal with trapping experiments of imidazol‐2‐ylidenes with carbon dioxide or carbon disulfide to form pseudo‐cross‐conjugated mesomeric betaines 17, 18…”

Thermolyzed products of naphth[1,2‐d]imidazo[2,1‐b]‐thiazole‐2,3‐dione

“…In contrast with these properties, we found that our product exhibited only the single carbonyl absorption band at 1690 cm-' in the ir region and one four-line system of aromatic protons at 6 7 The unfused 1,3,5,7-tetrazocine molecule was first prepared by Gompper and Schwarzensteiner [7], who assigned this novel ring skeleton in boat form conformation on the basis of X-ray diffraction analysis. As a symmetrically bifused ring system, it is reasonably to assume that the tetrazocine ring skeleton of compound 3 existed in the chair form conformation, though a crystallographic study showed that it is not suitable for X-ray analysis.…”

Electrospray ionization mass spectrometric studies of nucleophilic carbenes derived from pyrazolium and indazolium carboxylates

“…Very few reports, however, have appeared dealing with the decarboxylation of pseudo-crossconjugated heterocyclic mesomeric betaines. [14][15][16] Some very interesting reports of the reverse process deal with trapping experiments of imidazol-2-ylidenes with carbon dioxide or carbon disulfide to form pseudo-cross-conjugated mesomeric betaines. 17,18 Heterocyclic mesomeric betaines are defined as neutral conjugated compounds which can be represented exclusively by dipolar structures in which the positive and the negative charge are both delocalized within the p-electron system.…”