Condensation of acetonitrile into N-acetimidoylacetamidine promoted by a dinuclear nickel(ii) complex

Syntheses and Crystal Structures of Tetrakis(arylamidine)nickel(II) Chloride and Bis[2,4‐dipyridyl‐1,3,5‐triazapentadienato]nickel(II)

“…[20] However, there are only a few examples of transition metal complexes with the anionic 1,3,5-triazapentadienyl ligand [HNϭC(R)ϪNϭC(R)ϪNH] Ϫ . One complex is formed by the evaporation of a methanol solution of nickel chloride hexahydrate and acetamidine, [21] the second from reacting acetonitrile with a dinuclear nickel complex [Ni 2 (µ-OH) 2 (tpa) 2 ](ClO 4 ) 2 [tpa ϭ tris(2-pyridylmethyl)amine], [22] and the third from reacting triazine with copper acetate. [23] The synthetic route in this paper provides a new and convenient method for the preparation of complexes with 1,3,5-triazapentadienyl ligands.…”

Unsymmetrical NiII–Imidoylamidine Complexes Derived from a Novel Oxime‐Mediated Single‐Pot Reaction of Nitriles

“…Although some of the above-mentioned pathways for imidoylamidines are quite attractive (especially those which involve direct transformations of cheap and industrially available synthons like nitriles), [6,8,9] many of them still display significant drawbacks, such as the harsh reaction condi-A C H T U N G T R E N N U N G tions, [9a,b] low yields and selectivities, [6, 9a,b] require uncommon, expensive or/and moisture sensitive chemicals [9c, 10d-f] or particular metal complexes with complicated ligands, [6] and/ or involve amidines [4, 5a, 10a,e,f] and triazines, [5b, 10b,c] compounds obtained by the hazardous two-stage Pinner syntheses. [11] All the more important is that most of the synthesised "genuine" imidoylamidine complexes are symmetrical (B with equal R groups; Scheme 1, route I) and only rare examples of unsymmetrical imidoylamidines (namely generated on Pt centers by nitrile-amidine coupling) have been obtained.…”

“…Although a good number of complexes (mainly with Cu and Ni) possessing an imidoylamidine core with different substituent groups (e.g., guanide, amidinothiourea and amidino-O-alkylurea derivatives) is known [2,3] (C), the "genuine" imidoylamidine compounds remain less explored, probably due to the difficulties for their syntheses. [4] the information about such a type of compounds was rather scant [5] until 2001, when it was shown [6] that MeCN may undergo condensation into imidoylamidine species promoted by a dinuclear Ni-hydroxo complex bearing a pyridylamine ligand. At the same time, following our studies on the Zn II -and Co II -ketoxime-mediated transformations of nitriles to carboxamides, carboxylic acids and amidines, [7] and applying a similar synthetic strategy to the Ni II -ketoxime system, we have achieved an easy conversion of various alkylnitriles (RCN) into imidoylamidine complexes [Ni{N(H)= C(R)NHC(R)=NH} 2 ] 2 + .…”

Co(II) and Ni(II) complexes incorporating N-acetimidoylacetamidine ligand: Synthesis and structures

“…Ru(III) [16], Ta(III) [17] and two Cu(II) [18] com plexes of N acetimidoylacetamidine ligand have been prepared, but not characterized in detail. The only two compounds characterized by X ray diffraction are Ni[N{C(Me)=NH} 2 ] 2 ⋅ 1.5HCl ⋅ 3H 2 O [19] and Ni[N{C(Me)=NH} 2 ] 2 ⋅ 2H 2 O [14]. The formations of 1 and 2 enrich the chemistry of N acetimidoylaceta midine.…”

“…Due to nitrile group can be readily displaced or easily con verted into other groups, metal promoted reactions of nitrile have become a significant tool for the synthesis of a variety of diverse compounds [3][4][5][6][7][8][9][10][11][12][13]. In 2001, Kryatov [14] reported the synthesis of a nickel com plex, Ni(L) 2 ⋅ 2H 2 O (L = N{C(Me)=NH} 2 ), in which the ligand was derived by the self condensation of ace tonitrile and the condensation reaction was promoted by another nickel complex of [Ni 2 (μ OH) 2 (tmpa) 2 ] 2+ (tmpa = tris(2 pyridylmethyl)amine). As parts of our ongoing efforts on the synthesis of the cobalt and nickel complexes incorporating nitrogen rich ligand, we explored the reactions of cobalt and nickel salts with diphenylcarbazide in acetonitrile, and two new compounds of Co(L) 2 ⋅ CH 3 OH (1) and Ni(L) 2 ⋅ CH 3 OH (2) (HL = HN{C(Me)=NH} 2 ) were gener ated unexpectedly.…”