Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• show no hydrogen bonds in their crystal structures and only van der Waals interactions take place between the molecules. The bistetrazolium salt 9 (bromide salt of mesoionic compound 10) crystallizes in the trigonal space group , with 18 formula units in the unit cell. The asymmetric unit includes one

• the data for 1,3-di-alkyltetrazolium-5-aminide salts as described in the literature [25][26][28][32][33][34][35]. First of all, it should be mentioned that the formation of the salt from the corresponding mesoionic compound followed by protonation of the endocyclic N atom in all cases presented in

• carried out for compound 8a being the simplest mesoionic compound among the investigated ones in the present work. The atom numbering used in this section corresponds to that shown in Figure 2. The molecule of 8a can be represented by several Lewis structures (Scheme 3). To find the best Lewis structure

Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides

• Jan Szabo,
• Julian Greiner and
• Gerhard Maas

Beilstein J. Org. Chem. 2017, 13, 579–588, doi:10.3762/bjoc.13.57

• ···O8 (1−x, 1−y, 1−z), O11–Ha 0.95 Å, O11···O8 2.979(3) Å, Ha···O8 2.05 Å, <(O11–Ha···O8) 169°. Solid-state structure of mesoionic compound 7a (ORTEP plot); thermal displacement ellipsoids are drawn at the 30% probability level. Selected bond lengths (Å): C1–N1 1.343(1), C1–N3 1.398(1), C1–N5 1.322(1

From betaines to anionic N-heterocyclic carbenes. Borane, gold, rhodium, and nickel complexes starting from an imidazoliumphenolate and its carbene tautomer

• Ming Liu,
• Jan C. Namyslo,
• Martin Nieger,
• Mika Polamo and
• Andreas Schmidt

Beilstein J. Org. Chem. 2016, 12, 2673–2681, doi:10.3762/bjoc.12.264

• tautomer; imidazol-2-ylidene; mesoionic compound; mesomeric betaine; Introduction Since the first isolation of a stable N-heterocyclic carbene (NHC) [1] in 1991 this compound class has provided numerous highly efficient ligands of NHC-metal catalysts for cross-coupling reactions [2][3][4][5][6][7

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• to the mesoionic compound 5 under these conditions. Subsequent addition of a second, different imine produced β-lactams 9 in good yields, after heating at 55 °C for 24 h (Scheme 4) [4]. As mentioned above, imidazolinium salts 12 can be obtained by a dipolar cycloaddition of münchnone intermediates