Neuartige basische Liganden für die homogenkatalytische Methanolcarbonylierung, XXVI. Dynamisches und reaktives Verhalten von (Ether‐Phosphan)ruthenium(II)‐Komplexen in Abhängigkeit von der O‐Basizität

Abstract

Novel Basic Ligands for the Homogeneous Catalytic Carbonylation of Methanol, XXVIl). -Dynamic and Reactive Behaviour of (Ether-Phosphane)Ruthenium(II) Complexes in Dependence on the 0-Basicity Reaction of the ether-phosphane ligand Ph2PCH2C4H702 (3a) irradiation cis&, trans-6a is retransformed at 40°C into 4a via with C12Ru(PPh3), (2) results in the formation of the bis(che1ate) all-trans-?a and 5a. The latter and the corresponding comcomplex tran~-Cl~Ru(P"O)~ (4a). (P -0 = ql-P-coordinated; plexes 5b, e, containing THF and CH,0CH3 as ether substit-P"0 = q2-0,P-coordinated). With CO both Ru-0 bonds are uents, show fluxional behaviour. The coalescence temperacleaved to give all-tran~-Cl~Ru(CO)~(P-O), (?a). At 35°C 7a is tures (10, 80, and 55"C, resp.) and the estimated AG * values transformed into the rnonocarbonyl ruthenium complex trans-(52, 65, and 59 kJ/mol, resp.) of the exchange process indicate Cl,(PnO)(P-O)RuCO (5a) with elimination of one CO mole-the weakest Ru-0 contact in 5a compared to 5b, c. The lower cule. On heating all-trans-?a to 110°C in toluene the thermo-basicity of the dioxanyl function is also responsible for the dynamically more stable complex cis-C12(OC)2Ru(frans-different reaction behaviour of 4a, 5a, and ?a compared to the P N O )~ (6a) is obtained. All reaction steps are reversible. Upon corresponding complexes with the ligands 3b, c.

Synthesis and reactivity of cationic vinylidene and allenylidene ruthenium(II) complexes containing the phosphinoether Pri2PCH2CH2OMe as chelating ligand

“…The results of ligand-displacement reactions of compound 4 are summarized in Scheme 4. Lithium bromide and NaI as well as KCN react with 4 in methanol or dichloromethane by substitution of the chloride and partial opening of one of the chelate bonds to give the neutral vinylideneruthenium complexes 12, 13 and 15 in good yield. Although a six-fold excess of LiBr was used, the isolated product contains beside the dibromo derivative 15 the mixed bromo(chloro)ruthenium(n) compound 16 as a minor component (%:Ox).…”

“…If the reaction mixture described above was refluxed for 3 h red crystals of [ R ~I , ( K ~P , O -P ~~, P C H , C H , O M ~) , ] 14 were obtained (Found: C, 30. 13.2, J(HH) 6.9, PCHCH,)] and 1.18 [I2 H, dvt To a solution of compound 2 (0.262 g, 0.50 mmol) in tetrahydrofuran (10 cm3) were added HCzCCPh,OH (0.104 g, 0.50 mmol) and Ag(O,SCF,) (0.128 g, 0.50 mmol). After stirring for I5 h at room temperature in the dark the precipitate formed (AgCI) was filtered off through Kieselgur.…”

Ruthenium(II)-Komplexe mit dem neuen Liganden (Oxetanyl-2-methyl)diphenylphosphan / Ruthenium(II) Complexes with the Novel Ligand (Oxetanyl-2-methyl)diphenylphosphine

“…D a 1 im O xetan rest ü b er ein chirales K ohlenstoffatom verfügt, liefert das Leitet m an d urch eine C H 2C12-L ösung von 2 K ohlenm onoxid, so bildet sich u n te r Ö ffnung n u r einer R u -O -B in d u n g u n d U m lag eru n g der (E ther-P hosphan)-L iganden von cis nach trans q u an titativ der gelbe M onocarbonylruthenium (II)-K om plex 3 (Schem a 1). Dieser R eak tio n sv erlau f steht im G egensatz zur Synthese e n t sprechender M onocarbonylruthenium (II)-K omplexe m it E ther-P hosphanen geringerer O-Basizitä t, in denen u n ter denselben Bedingungen sofort beide R u -O -K o n ta k te u n ter Bildung der all-trans-K om plexe C l2R u (C 0 )2( P~0 ) 2 gelöst w erden [1,3,4]. Die hohe O -B asizität des O xetans spiegelt sich in der Lage der Bande der C O -A bsorption im IR -S p ek tru m von 3 wider, die gegenüber allen a n deren derartigen K om plexen bei niedrigsten W el lenzahlen erscheint.…”

“…A us tem peraturabhängigen 3 IP {'H }-N M R -S p ektren ergab sich, daß die lösungsm ittelähnliche E th er-F u n k tio n T H F am stärksten [3,4] u n d der 1,3-D ioxanylrest am schw ächsten [1] an das R u-A to m koordiniert sind. L etzterer fü h rt schon bei sehr niedrigen T em peraturen zu dynam ischem V erhalten.…”