α-Addition von Aminen, Iminen und Hydrazinen an Allenyliden-Komplexe — Bildung von Carben-, Azetidinyliden- und Nitril-Komplexen

Abstract

Diarylallenylidene(pentacarbonyl)-chromium and-tungsten complexes, (CO)sM=C=C=CR 2 (M = W (1), Cr (2», react with amines, imines and hydrazines by addition of the nitrogen nucleophile to the C" allenylidene atom. With NEt3 the adduct formation is reversible. With secondary and primary amines, imines and hydrazines, the initially formed N-ylide complexes react readily further to give carbene, azetidinylidene and nitrile complexes, respectively. For example the reaction of (a) 1 and 2 with HNEt2 or HzNPh gives alkenyl(amino}carbene complexes, (CO)sM=C[C(H)=CR z ] NR z (3-5); (b) of 1 and 2 with HN=CR'2 gives alkenyl(al-kylideneamino}carbene complexes, (CO)sM=C[C(H)=CR z ] [N=CR z ] (6,7); (c) of 1 with CPr)N=C(Ph)H the azetidinylidene complex 9; (d) of 1 with 1,2-disubstituted hydrazines such as H(Me)NN(R)H (R = Me, Ph) alkenyl(hydrazino)carbene complexes, (CO)sW=C[C(H)=CR 2 ] [N(Me)N(R)H] (11) and (e) of 1 with H z NNR 1 R 2 (R 1 = R2 = H, Me; Rl = H, R2 = Ph) alkenyl(amino)carbene complexes (13) and/or acrylnitrile complexes, (CO)sW[N = C-C(H)=CR 2 ] (12). The structures of representative examples of 6, 11 and 12 were established by X-ray analyses. Zusammenfassung Diarylallenyliden(pentacarbonyl)chrom-und-wolfram-Komplexe, (CO)sM=C=C=CR 2 (M = W (1), Cr (2», reagieren mit Aminen, Iminen and Hydrazinen unter Addition des Stickstoffnukleophils an das C,,-A1lenylidenatom. Die Adduktbildung ist mit NEt3 reversibel. Mit sekundaren und primaren Aminen, Iminen und Hydrazinen reagieren die zunachst gebildeten N-Ylidkomplexe rasch weiter zu Carben-, Azetidinyliden-bzw. Nitril-Komplexen. So erhalt man z. B. bei der Reaktion von (a) 1 und 2 mit HNEt2 oder H 2 NPh Alkenyl(amino}carben-Komplexe, (CO)sM=C[C(H)=CR 2 ]NR z (3-5); (b) von 1 und 2 mit HN=CR z A1kenyl(al-kylidenamino}carben-Komplexe, (CO)sM=C[C(H)=CR 2 ] [N=CR z ] (6, 7); (c) von 1 mit (ipr)N=C(Ph)H den Azetidinyliden-Komplex 9; (d) von 1 mit 1,2-disubstituierten Hydrazinen wie H(Me)NN(R)H (R = Me, Ph) Alkenyl(hydrazino)carben-Komplexe, (CO)s W=C-[C(H)=CR 2 ] [NMeN(R)H] (11); und (e) von 1 mit H2NNRIR2 (R 1 = R2 = H, Me; Rl = H, R2 = Ph) A1kenyl(amino)carben-Komplexe (13) und/oder Acrylnitril-Komplexe, (CO)sW[N=C-C(H)=CR 2 ] (12). Die Strukturen reprasentativer Beispiele von 6, 11 und 12 wurden durch Riintgenstrukturanalysen gesichert.

Ferrocenyl-substituted allenylidene complexes of chromium, molybdenum and tungsten: Synthesis, structure and reactivity

“…A similar C a C b addition was observed in the reactions of diethylamine with diarylallenylidene complexes [(CO) 5 M@C@C@C(Aryl) 2 ] (M Cr, W) [11] and of dimethylamine with [(CO) 5 Cr@C@C@C(NR 2 )Ph] (R Et. i-Pr) [12].…”

“…The UV Vis spectra were recorded on a Hewlett Packard 8452A diode array spectrophotometer. The following compounds were prepared according to literature procedures: di(ferrocenyl)ketone [17], 1,1-diferrocenyl-3-(trimethylsilyl)-prop-2-in-ol [18], 1,1-diferrocenyl-3-prop-2-in-ol [18], 1-ferrocenyl-1-phenyl-prop-2-in-1-ol [19] and the complexes [(CO) 5 M(THF)] [11], 3a [20], 6a [6], 8a [21] and formylferrocene [22] were prepared according to published methods. All other chemicals were used as obtained from commercial suppliers.…”

(Acetonitrile-κN)pentacarbonyltungsten(0)

“…For other structures with an (alkyl nitrile-N)pentacarbonyltungsten(0) fragment, see: Darensbourg et al (1992); Reibenspies et al (1994); Jefford et al (1996). For structures with conjugated nitriles, see: Fischer et al (1993); Helten et al (2010) and for structures with nitriles that are part of an organometallic complex, see: Busetto et al (1992); Duclos et al (1999); Tang et al (1999); Trylus et al (1999); Cordiner et al (2006). For the preparation, see: Strasser et al (2010).…”

“…E67, m772 When the present molecular structure of [W(CH 3 CN)(CO) 5 ] is compared to other literature examples of (nitrile-κN)pentacarbonyltungsten(0) compounds, surprisingly no significant variations in bond lengths can be observed within the metal-ligand bonds despite different electronic and steric properties of the nitriles used. Related crystal structures reported include the W(CO) 5 adducts of alkylnitriles (Reibenspies et al, 1994;Jefford et al, 1996), conjugated nitriles (Fischer et al, 1993;Tang et al, 1999;Cordiner et al, 2006;Helten et al, 2010), α-metal-substituted alkyl nitriles (Busetto et al, 1992;Trylus et al, 1999) as well as deprotonated 2,3,4-tricyanopent-2-enedinitrile (Duclos et al, 1999).…”

From alkenylphosphane aminoallenylidene ruthenium(II) complexes to highly unsaturated ruthenaphosphabicycloheptene complexes

“…These derivatives have a great potential to promote novel carbon-carbon and carbon-heteroatom coupling reactions because of the electrophilic (C a and C c ) and nucleophilic (C b ) character of the carbon nuclei of the allenylidene chain. Furthermore, the stoichiometric cycloadditions of allenylidene transition metal complexes are also well-known processes, though they have been much less explored [2][3][4]. In particular, allenylidene ruthenium complexes are able to promote selective cycloaddition processes between the cumulene function and C@N, and C@C substrates [5,6].…”