Derivatives of the triaminoguanidinium ion, 3. Multiple N-functionalization of the triaminoguanidinium ion with isocyanates and isothiocyanates

• Jan Szabo,
• Kerstin Karger,
• Nicolas Bucher and
• Gerhard Maas

Beilstein J. Org. Chem. 2014, 10, 2255–2262, doi:10.3762/bjoc.10.234

• 7a and 8 show interesting solid-state structures with intra- and intermolecular hydrogen bonds. Keywords: aryl isocyanate; aryl isothiocyanate; carbamoylation; sulfonyl isocyanate; triaminoguanidinium salt; 1H-1,2,4-triazole-5(4H)-thione; Introduction The 1,2,3-triaminoguanidinium ion, [C(NHNH2)3

• inside a cavity of the cation, being fixed there by three N–H···Cl hydrogen bonds; this suggests that the cation can also serve as a receptor for other anions of appropriate size and shape. The triaminoguanidinium salt 7a was easily deprotonated to afford the corresponding neutral tris(ureido)guanidine 8

• -triaminoguanidine. Attempts to convert 9 into the corresponding triaminoguanidinium salt with strong acids failed. Structural and NMR data of guanidinium salts 7 and guanidine derivative 8 The solid-state structures of guanidinium salt 7a and the neutral guanidine derivative 8 display a common structural motif: the