Metal-mediated cyanamide-hydroxyguanidine coupling

Reaction of the cyanamides R2NCN (R = Me 2a, Et 2b) with the hydroxyguanidine OC4H8NC(=NOH)NH2 (1) in the presence of zinc halides leads to [ZnX2{HN=C(NR2)ON=C(NH2)NC4H8O}] derived from the Zn-II-mediated cyanamide-hydroxyguanidine coupling. This reaction is the first observation of interplay between any nitrile group and any hydroxyguanidine both in metal-involving and metal-free chemistry. Complexes 3a,b-5a,b rather rapidly degrade in solutions at RT, but solvates 3a,b center dot MeOH and 4a center dot MeOH are sufficiently stable in the solid state and they were characterized by IR, HRESI+-MS, solid state CP-MAS TOSS C-13 NMR, and X-ray crystallography (for 3a,b). Complexes 4b and 5a,b were identified in solutions by HRESI+-MS. (C) 2014 Elsevier B.V. All rights reserved.