.sigma.2-N', .mu.2-N, .eta.2-C:N Coordination as the activating step in the carbon-carbon bond formation between two .alpha.-diimines in dinuclear ruthenium carbonyl complexes. X-ray structure of tetracarbonylbis[glyoxalbis(isopropylimine)]diruthenium

1,3-Dipolar cycloaddition to the FeSC fragment 20. Preparation and properties of carbonyliron complexes of di-thiooxamide. Reactivity of the mononuclear (di-thiooxamide)Fe(CO)3 towards dimethyl acetylenedicarboxylate

“…The h 2 -C S coordinated thiocarbonyl carbon atom resonance, observed at 95.7 ppm, is shifted 91.4 ppm to lower frequency. These shifts are typical for a s-S, m 2 -S, h 2 -C S co-ordination of the DTO ligand and have also been observed for the isostructural complexes M 2 (CO) 6 (L) (Fe, Ru, Os; L = R-DAB, aimino-ketone and ester) [33,52,53,55,85].…”

Preparation and Properties of Carbonyliron Complexes of 1-Aza-4-oxa-1,3-butadiene (α-Imino Ketone) – X-ray Crystal Structures of Fe(CO)3[MeNC(Ph)C(Ph)=O] and Fe2(CO)4[tBuNC(H)(Me)C(O)(O)C(Me)C(H)=NtBu]

“…[1][2][3][4][5] The ability to donate the nitrogen lone pairs and the (CϭN) imine π-bonds results in a flexible coordination behaviour in which the α-diimine ligand can donate from 2 to 8 electrons to one or more metal centres. An interesting aspect of this versatile coordination behaviour is the activation of the imine bond towards C-C, C-H, C-N, and N-H coupling reactions of R-DAB ligands in the coordination sphere of transition metals with a variety of unsaturated molecules, such as α-diimines [6][7][8][9][10] carbodiimides [11] sulfines, [11] and alkynes. [12][13][14][15][16][17][18] In a series of previous papers [19][20][21][22][23][24] we have reported in detail on the C-C coupling reaction of the [(R-DAB)Fe(CO) 3 ] complexes 1 (cf.…”

“…[28] In these complexes, as well as in the free ligand, the NϭC-CϭO moiety has a gauche conformation with a torsion angle of approximately 90°around the central C-C bond, which is attributed to a minimising of the steric repulsion between the skeleton substituents. The reaction of Fe 2 (CO) 9 with the closely related α-imino ester PhCH(Me)NϭC(H)C(OEt)ϭO (L*), as described by Weiss et al, [29] resulted in the formation of two dinuclear products, Fe 2 (CO) 6 (L*) (4) and the C-C coupled complex Fe 2 (CO) 6 (L*-L*) (5) (cf. Scheme 2).…”

“…In this paper we report on the reactions of α-imino ketones (L) with Fe 2 (CO) 9 , which results in the formation of the mononuclear chelate complexes [Fe(CO) 3 (α-imino ketone)] (6) and the dinuclear complexes [Fe 2 (CO) 6 (α-imino ketone)] (7) and [Fe 2 (CO) 4 (L-L)] (8). Complexes 8 contain two α-imino ketone ligands which are C-C-coupled at the ketone carbon atoms.…”

Ruthenium-Komplexe mit Diazadienen, IX. Ein neuartiger Chromophor aus zwei Diazadien-Ruthenium-Einheiten — Struktur und Eigenschaften von [(CO)2(DAD)CH3Ru- RuCH3(DAD)(CO)2] (DAD = ipr—N=CH—CH=N —ipr) / Ruthenium Complexes with Diazadienes, IX. A New Chromophore from Two Diazadiene Ruthenium Units — Structure and Properties of [(CO)2(DAD)CH3Ru -RuCH3(DAD)(CO)2] (DAD = ipr-N = CH -CH = N -ip r)

“…Während sich 3a, 5a und 6a völlig analog verhal ten, ergibt die Reduktion eines Komplexes 3b mit einem deutlich sperrigeren DAD (R = (ipr)2CH) keine isolierbare Ruthenium(I)-Verbindung. Das stimmt im übrigen mit Beobachtungen von Vrieze et al überein, wonach bei der Umsetzung von Ru3(CO) 12 mit kleinen DAD relativ leicht Dimere [(DAD)Ru(CO)2]2 10 mit brückenständigen DAD als 6 e~-Donatoren erhalten werden, ein Komplex typ, der für sperrigere DAD nicht bekannt ist [7]. Diese Dimeren wurden als Folgeprodukte der che mischen Reduktion von 1 auch nur für kleine DAD von uns beobachtet.…”