Metal-Promoted Nucleophilic Addition and Cyclization of Diamines with Dicyanonitrosomethanide, [C(CN)(2)(NO)](-)

The metal-promoted nucleophilic addition of diaminoalkanes to dicyanonitrosomethanide, C(CN)(2)(NO)(-)(denm), and subsequent cyclization has been utilized in the synthesis of novel anionic species. The addition and cyclization of 1,2-diaminoethane (en) to both nitrile groups of denm forms the anion diimidazolinylnitrosomethanide (dinm), isolated ill the dinuclear complex [{Cu(dinm)(en)}(2)en][ClO4](2) (1). The same reaction solution yields [Cu-(cinm)(ainm)] (cinm=cyanoimidazolinylnitrosomethanide, ainm = (((2-ami-noethyl)amino)iminomethyl)imidazolinylnitrosomethanide) (2), which contains intermediates of the dinm species, supporting a stepwise mechanism of addition of the diamine followed by cyclization. 1,3-Diaminopropane (pn) added and cyclized on only one nitrile group to form a 1,4,5,6- tetrahydropyrimidine ring. This resulted in the formation of the cyanonitroso-1,4,5,6-tetrahydropyrimidinylmethanide ligand (cnpm) in complexes with the general formula [M(cnpm)(2)(pn)] (M=Cu (3a), Ni (3b), Zn (3c)). These reactions are contrasted to the addition of ethanolamine in the pyridine (py) complex [Ni-(chnm)(2)(py)(2)]center dot(py) (4) (chnm=cyano((2-hydroxyethyl)amino)imino-methylnitrosomethanide) with no cyclization, demonstrating the higher reactivity of amines compared with alchols. The formation of the complexes [M(cmnm)(2)(mame)] (M=Co (5a), Ni (5b), cmnm=cyano(imino-(methyoxy)methyl)nitrosomethanide, mame = 1-dimethylamino-2-methylaminoethane) indicate mame may be too sterically hindered to denm under similar reaction conditions.