19705-90-9Relevant academic research and scientific papers
Transformation of aziridinocarbene complexes of chromium and tungsten into nitrile complexes and olefins
Denise, B.,Parlier, A.,Rudler, H.
, p. C23 - C32 (1988)
Carbene complexes of chromium and of tungsten bearing the methylaziridine group on the carbene carbon atom undergo a thermal rearrangement with elimination of propene to give nitrile complexes of the metals.
Chemistry of 2H-azaphosphirene complexes, 16. - Syntheses, structures, and reactions of C-methoxycarbonyl-functionalized small- and medium-sized P- heterocycle complexes
Streubel,Wilkens,Rohde,Ostrowski,Jeske,Ruthe,Jones
, p. 1567 - 1579 (2007/10/03)
Thermal ring-opening of [{2-bis(trimethylsilyl)methyl-3-phenyl-2H- azaphosphirene-κP}pentacarbonyltungsten(0)] (8a) in the presence of dimethyl acetylenedicarboxylate (DMAD) led to the 2,3-bifunctionalized 1H- phosphirene complex 9a and the 4-phenyl-substituted 2H-1,2-azaphosphole complex 10a, the latter as a by-product. If a small amount of benzonitrile was added, complex 10a was obtained as the main product, along with a small amount of the decomplexed 2H-1,2-azaphosphole 11, which could not be isolated. Reaction of complex 10a with elemental sulfur furnished the corresponding P(v) sulfide 13. When the ring-opening of complex 8a was performed in the presence of two equivalents of DMAD and two equivalents of dimethyl cyanamide, we obtained the 4-dimethylamino-substituted 2H-1,2- azaphosphole complex 10b, together with the diastereomeric AS-1,3,2- oxazaphospholene complexes 14a,b. On reaction of [{2- pentamethylcyclopentadienyl-3-phenyl-2H-azaphosphirene- κP}pentacarbonyltungsten(0)] (8b) and DMAD in toluene, the corresponding 1H-phosphirene complex 9b was only formed as a transient species and the P- coordinated P,C-cage compound 15 was the final product. Using benzonitrile as solvent, the 4-phenyl-substituted 2H-1,2-azaphosphole complex 10c was obtained, together with the 7-aza-1-phosphanorbornadiene complex 16, the latter through partial decomposition of 10c coupled with rearrangement and a Diels-Alder reaction; the ratio 10c/16 was found to depend strongly on the molar ratio of complex 8b to DMAD. A cycloaddition reaction of the 2,3- bifunctionalized 1H-phosphirene complex 9a with 2,3-dimethylbutadiene furnished the bicyclic phosphirane complex 19, along with a small amount of the noncoordinated bicyclic phosphirane 20. Reaction of complex 9a with diethylamine yielded the phosphirane complex 21 as a 1,2-addition product, the diorganophosphane complex 22 through ring-opening of 9a, and the 3,4- functionalized 1,2-dihydro-1-phosphet-2-one complex 23 through an unprecedented ring-expansion reaction, the products 21, 22, 23 were formed in a ratio of ca 1:1.1. The structures of the 1H-phosphirene complex 9a, the 4- dimethylamino-substituted 2H-1,2-azaphosphole complex 10b, the bicyclic phosphirane complex 19, the phosphirane complex 21, and the 1,2-dihydro-1- phosphet-2-one complex 23 have been determined by single-crystal X-ray diffraction analysis.
Organic syntheses via transition metal complexes. 78. Hydrazinolysis of alkynylcarbene complexes of chromium and tungsten. Formation of hydrazinocarbene, imidate, pyrazolidinylidene, and nitrile complexes
Aumann, Rudolf,Jasper, Beate,Fr?hlich, Roland
, p. 2447 - 2455 (2008/10/09)
Hydrazinolysis of alkynylcarbene complexes (CO)5M=C(OEt)C≡Ph (1, M = W; 1′, M = Cr) with mono- and 1,2-dimethylhydrazine MeHNNHR (2a,b) (R = Me, H) affords three different-type compounds: hydrazinocarbene complexes (CO)5M=C(NMe-NHR)C≡CPh [(E/ Z)-3a,b], imidate complexes (CO)5M[MeN=C(OEt)-C≡CPh] [(E/Z)-4a], and pyrazolidinylidene complexes 5a,b. Hydrazinolysis of 1/1′ with 1,1-dimethylhydrazine or (unsubstituted) hydrazine H2NNR2 (2c,d) (R = Me, H) yields hydrazinocarbene complexes (CO)5M=C(NH-NR2)C≡CPh [(E/Z)-3c], imidate complexes (CO)5M[HN=C(OEt)C≡CPh] [(E/Z)-4a], and benzonitrile complexes (CO)5M(N≡CPh) (8). Hydrazinolysis of 1 with H2NNHR (2e,f) (R = COMe, Ph) gives pyrazoles 12e,f as the only products. The product composition of the reactions of 2a-d with 1 is markedly influenced by the reaction temperature. Reaction of 1 with N- and O-methylhydroxylamines (13, 14) affords imidate complexes 4 only. The hydrazinocarbene complexes (E)-3a and (Z)-3c were characterized by X-ray diffraction. Both compounds crystallize in space group P1 (No. 2): (E)-3a, C16H12N2O5W, cell parameters a = 8.501(2) ?, b = 9.645(2) ? c = 11.860(2) ?, α = 103.56(2)°, β = 95.59(2)°, γ = 111.76(2)°, Z = 2, R1 = 0.043, and wR2 = 0.083; (Z)-3c, C16H12N2O5W, cell parameters a = 9.380(3) ?, b = 9.685(4) ?, c = 10.804(3) ?, α = 84.77(5)°, β = 80.74(3)°, γ = 66.47(3)°, Z = 2, R1 = 0.036, and wR2 = 0.086.
Organic Syntheses via Transition Metal Complexes, 55. - 5-Aza-1-metalla-1,3,5-trienes of Chromium and Tungstena and Their Cyclization to 2H-Pyrrole Complexes
Aumann, Rudolf,Heinen, Heinrich,Goddard, Richard,Krueger, Carl
, p. 2587 - 2594 (2007/10/02)
5-Aza-1-metalla-1,3,5-trienes 5 and 6 are obtained in two steps from aminocarbene complexes 1 .The first step involves the condensation of 1 with benzaldehyde (2) in the presence of TiCl4/Et3N to give 3-aza-1-metalla-1,3-dienes 3 (LnM=C-N=C). 3 adds to the 1-aminoalkyne 4 to give 5 and 6 by a chain extension of two carbon atoms.The trans isomers 5 are formed as the major products and are stable both in the solid state and in solution.The cis isomers 6 undergo a novel-type cyclization to give 2H-pyrrole complexes 8.Triene 5b was characterized by an X-ray analysis. Key Words: Aminocarbene complexes, of chromium and tungsten / 3-Aza-1-metalla-1,3-dienes, of chromium and tungsten / 5-Aza-1-metalla-1,3,5-trienes, cyclization to 2H-pyrroles / 2H-Pyrrole complexes, of chromium and tungsten / Pyrroles, syntheses by metal-induced cycloaddition reactions
Formal nitrogen hydride insertion into the metal-carbene bond of fischer-type carbene complexes
Raubenheimer, Helgard G.,Kruger, Gert J.,Scott, Fred,Otte, Ronald
, p. 1789 - 1795 (2008/10/08)
A series of imidate complexes [(CO)5M{NH=C(OR1)R2)] (M = W, R1 = Me or Et, R2 = Ph; M = W, R1 = Me, R2 = Me; M = Cr, R1 = Me or Et, R2 = Ph) can be prepared by reaction of alkoxyorganocarbene complexes with S,S-diphenylsulfilimine, NH=SPh2. The thiocarbene complex [(CO)5W{C(SPh)R2)] (R2 = Me) similarly gives the corresponding thioimidate complex, but when R2 = Ph, [(CO)5W(NCPh)] (9) is the only product. The heterometallocyclic complex [(CO)4W{C(OEt)C(OEt)=CS(CH2)3S}] also undergoes NH insertion and concomitant chelate ring enlargement. The imidate complex [(CO)5W{NH=C(OMe)Ph}] (1) is deprotonated by Bu-, H-, MeO-, and RS- to afford the nitrile (9), but with dimethylamine the amidine complex [(CO)5W{NH=C(NMe2)Ph}] (13) is formed by aminolysis. The Z isomer of 1 and the E isomer of 13 are completely characterized by X-ray structure determinations. Crystal data for 1: WC13H9NO6, Mr 459.07, monoclinic, space group P21/c, a = 10.694 (4) ?, b = 6.650 (1) ?, c = 20.338 (4) ?, β = 92.18 (3)°, V = 1445 ?3, Z = 4, Dcalcd = 2.11 g cm-3. Crystal data for 13: WC14H12N2O5, Mr 472.118 monoclinic, space group P21/c, a = 11.723 (2) ?, b = 9.550 (1) ?, c = 15.032 (6) ?, β = 105.43 (3)°, V = 1622 ?3, Z = 4, Dcalcd = 1.93 g cm-3. The W-N(sp2) bond lengths are 2.249 (5) and 2.243 (5) ?. Reaction of NH=SPh2 with [M(CO)6] (M = Cr or W) produces yellow solutions from which [(CO)5M(SPh2)] can be isolated. In the presence of PPh3 only the monosubstituted phosphine complexes form in less than 50% yields.
KINETISCHE UND MECHANISTISCHE UNTERSUCHUNGEN VON UEBERGANGSMETALL-KOMPLEX-REAKTIONEN XXII. KONKURRENZ ZWISCHEN DISSOZIATIVEM UND ASSOZIATIVEM MECHANISMUS BEI DER REAKTION VON PENTACARBONYL(DIPHENYLCARBEN)WOLFRAM MIT NITRILEN
Fischer, Helmut,Zeuner, Siegfried
, p. 63 - 76 (2007/10/02)
The reaction of pentacarbonyl(diphenylcarbene)tungsten, (CO)5W=CPh2 (I), with organyl nitriles, (II) (R = C6H4NMe2-p (a), C6H4OMe-p (b), Ph (c), Me (d), But (e)), yields the insertion product (CO)5W (III), the nitrile complexes (IV) and (V) and diphenyl ketene, Ph2C=C=O.The product distribution depends on the type and the concentration of the organyl nitrile II.At constant temperature, the yield of III increases and that of IV as well as that of diphenyl ketene decreases with increasing concentration of II and in the order IId, IIc, IIb, IIa.When I reacts with IIb in the presence of 13CO, 13CO is incorporated almost exclusively into IVb.At 50.6 deg C in 1,1,2-trichloroethane, the reaction of I with IIa-d follows an additive rate law: -d/dt = k1 + k2.The rate constant k1 is independent of the type of II and agrees well with the rate constant for the dissociative thermolysis of I in 1,1,2-trichloroethane, however, k2 clearly increases in the series IId-a.A reaction scheme is proposed consisting of an associative pathway (giving III) and a dissociative pathway leading to the compounds IV, V and diphenyl ketene.
STABILE IMINE COMPLEXES OF TUNGSTEN CARBONYLS
Czarkie, Dorotha,Shvo, Youval
, p. 123 - 128 (2007/10/02)
Ketimine and aldimine complexes of pentacarbonyltungsten(0) were obtained from a reaction of (CO)5W*THF with ketoximes and aldoximes ,respectively.Pentacarbonylacetaldiminetungsten(0) was isolated in the solid state, while the formaldimine complex was detected in solution.
