Synthesis, reactivity and catalytic activity in transfer hydrogenation of ketones of ruthenium(ii) and ruthenium(iv) complexes containing the novel N-thiophosphorylated iminophosphorane-phosphine ligands Ph2PCH2P{?NP(?S)(OR)2}Ph2 (R = Et, Ph)Electronic supplementary information (ESI) available: a... (original) (raw)
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Organometallics, 2001
DMSO)] (6b) in good yield. The crystal structures of 1a and 5b have been determined by X-ray diffraction. Compound 2a, containing two labile DMSO ligands, has been used as a precursor to synthesize the derivatives [RuCl 2 (κ 2 -P,N-2-Ph 2 PC 6 H 4 CHdN t Bu)L] [L ) PPh 3 (1a); PPh 2 Me (3a); PMe 2 Ph (4a)]. Complexes 1a, 2a, 5b, and 6b are active in catalytic transfer hydrogenation of aryl-alkyl and dialkyl ketones in propan-2-ol. The five-coordinate complexes 1a, 5b, and 6b show higher catalytic activity than the octahedral complex 2a. Complexes 1a and 5b are more efficient catalysts than the precursor complex [RuCl 2 (PPh 3 ) 3 ]. For the best catalyst, 1a, yields up to 91% were obtained and turnover frequencies may be as high as 41 400 h -1 .
Inorganic Chemistry, 2003
Inorganic Chemistry, 2007
The half-sandwich complexes [(η 5-C 5 H 5)RuCl(DPEphos)] (1) and [{(η 6-p-cymene)RuCl 2 } 2 (µ-DPEphos)] (2) were synthesized by the reaction of bis(2-(diphenylphosphino)phenyl) ether (DPEphos) with a mixture of ruthenium trichloride trihydrate and cyclopentadiene and with [(η 6-p-cymene)RuCl 2 ] 2 , respectively. Treatment of DPEphos with cis-[RuCl 2-(dmso) 4 ] afforded fac-[RuCl 2 (κ 3-P,O,P-DPEphos)(dmso)] (3). The dmso ligand in 3 can be substituted by pyridine, 2,2′-bipyridine, 4,4′-bipyridine, and PPh 3 to yield trans,cis-[RuCl 2 (DPEphos)(C 5 H 5 N) 2 ] (4), cis,cis-[RuCl 2 (DPEphos)-(2,2′-bipyridine)] (5), trans,cis-[RuCl 2 (DPEphos)(µ-4,4′-bipyridine)] n (6), and mer,trans-[RuCl 2 (κ 3-P,P,O-DPEphos)-(PPh 3)] (7), respectively. Refluxing [(η 6-p-cymene)RuCl 2 ] 2 with DPEphos in moist acetonitrile leads to the elimination of the p-cymene group and the formation of the octahedral complex cis,cis-[RuCl 2 (DPEphos)(H 2 O)(CH 3 CN)] (8). The structures of the complexes 1−5, 7, and 8 are confirmed by X-ray crystallography. The catalytic activity of these complexes for the hydrogenation of styrene is studied.
Organometallics, 2004
The mixed-phosphine complexes [Ru(η 5 -C 9 H 7 )Cl{κ 1 (P)-Ph 2 P(CH 2 CRdCH 2 )}(PPh 3 )] (R ) H (1a), Me (1b)) are prepared by phosphine exchange reactions (1:1 molar ratio) of [Ru(η 5 -C 9 H 7 )Cl(PPh 3 ) 2 ] with the corresponding allylphosphines Ph 2 P(CH 2 CRdCH 2 ) in refluxing THF. The reaction of 1a with sodium methoxide in methanol yields the hydride derivative [Ru-(η 5 -C 9 H 7 )H{κ 1 (P)-Ph 2 P(CH 2 CHdCH 2 )}(PPh 3 )] (1c). The treatment of complexes 1a and 1b with NaPF 6 in methanol diastereoselectively affords the cationic complexes [Ru(η 5 -C 9 H 7 )-{κ 3 (P,C,C)-Ph 2 P(CH 2 CRdCH 2 )}(PPh 3 )][PF 6 ] (R ) H (2a), Me (2b)) in good yield. An X-ray crystal structure determination of complex 2a shows that the si enantiofacial coordination of the olefin group accompanies the R relative configuration of the metal center. No epimerization process has been observed. Olefin exchange substitution reactions of complex 2a with MeCN and BzCN (1:1.5 molar ratio) in refluxing CH 2 Cl 2 yield the cationic complexes [Ru(η 5 -C 9 H 7 )(NCR){κ 1 (P)-Ph 2 P(CH 2 CHdCH 2 )}(PPh 3 )][PF 6 ] (R ) Me (3a), Bz (3b)). Similarly, the neutral complexes [Ru(η 5 -C 9 H 7 )(N 3 ){κ 1 (P)-Ph 2 P(CH 2 CRdCH 2 )}(PPh 3 )] (R ) H (4a), Me (4b)) are obtained by the treatment of complexes 2a,b with sodium azide in THF/MeOH at room temperature. The addition of lithium carbanions LiR′ (R′ ) Me, nBu) to solutions of complexes 2a,b in tetrahydrofuran results in regio-and stereoselective exo addition at the C atom of the coordinated allylic group, affording the ruthenacyclopentane complexes [Ru-(η 5 -C 9 H 7 ){κ 2 (P,C)-Ph 2 P{CH 2 C(R)(R′)CH 2 }}(PPh 3 )] (R ) H, R′ ) Me (5a), nBu (5b); R ) Me, R′ ) Me (6a), nBu (6b)) in 80-95% yield. Similarly, the complexes [Ru(η 5 -C 9 H 7 ){κ 2 (P,C)-Ph 2 P{CH 2 CH(R)CH 2 }}(PPh 3 )] (R ) H (5c), Me (6c)) are formed by the reaction of equimolar mixtures of complexes 2a,b with Li[B(C 2 H 5 ) 3 H]. The molecular structure and relative configurations R Ru S/S Ru R of the new stereogenic atoms of complex 5b have been determined by X-ray diffraction. Kinetic studies on the substitution reaction of complex 2a with CD 3 CN in CDCl 3 indicate that the olefin exchange occurs via parallel first-order (dissociative) and second-order (associative) pathways and highlight the intermediacy of a transient coordinatively unsaturated species, formed by olefin dissociation before attack of the nitrile.
Organometallics, 2005
The cis-[RuCl 2 (PPh 3 ) 2 (N-N)] (N-N ) bipy (1), Me-bipy (2), phen (3), and bathophen (4)) complexes were used to synthesize five new electron-rich phosphine-containing complexes cis-[RuCl 2 (dcype)(N-N)] (N-N ) bipy (1a), Me-bipy (2a), phen (3a), and bathophen (4a)) and cis-[RuCl 2 (PEt 3 ) 2 (bipy)] (1c) by phosphine exchange. These complexes were obtained and characterized by NMR ( 31 P{ 1 H}, 1 H), cyclic voltammetry, and elemental analysis. Electrochemical studies of these complexes reveal a single reduction process (Ru III /Ru II ). These complexes are more easily oxidized than their analogues cis-[RuCl 2 (dppb) ]. The reactivity of complexes cis-[RuCl 2 (dcype)(N-N)] with carbon monoxide was tested, and dissociation of one chloride was observed, leading to the formation of four new cationic species with general formula [RuCl(CO)(dcype)(N-N)](PF 6 ) (bipy (1b), Me-bipy (2b), phen (3b), and bathophen (4b)). The complexes described here and elsewhere with general formulas cis-[RuCl 2 (P-P)(N-N)], [RuCl(CO)(dcype)(N-N)](PF 6 ), and cis-[RuCl 2 (P) 2 (N-N)] were used as precatalysts in the transfer hydrogenation of functionalized aryl-ketones, and most of them were active. X-ray structures of cis-[RuCl 2 (PEt 3 ) 2 (bipy)] (1c) and [RuCl(CO)(dcype)(bipy)]-(PF 6 ) (1b) will be presented.
Organometallics, 2015
The coordination of the phosphino-alcohol ligands 2-Ph 2 PC 6 H 4 CH(R)OH (R = H, Me) onto an arene-ruthenium(II) fragment gave rise to the formation of complexes of general formula [RuCl 2 {2-Ph 2 PC 6 H 4 CH(R)OH}(η 6 -arene)] (R = H, arene = C 6 H 6 (3a), p-cymene (3b), mesitylene (3c), C 6 Me 6 (3d); R = Me, arene = p-cymene (5b)). In solution, different isomers were observed depending on the solvent polarity. They arise from the different coordination modes adopted by the phosphino-alcohol: (i) the classical κ 1 -P mode through the selective coordination of the phosphorus atom, (ii) the establishment of both Ru−P and Cl····H−O interactions, and (iii) the P,O-chelate formation. Treatment of these species with NaPF 6 led to the selective formation of the corresponding cationic species [RuCl{κ 2 -(P,O)-2-Ph 2 PC 6 H 4 CH(R)OH}(η 6 -arene)][PF 6 ] 6a−d and 7b, respectively. Unexpectedly, under basic conditions these cationic compounds evolved into the neutral α-hydroxy-alkyl derivatives [RuCl{κ 2 -(P,C)-Ph 2 PC 6 H 4 C(R)OH}(η 6 -arene)] through a formal C−H bond activation process.
Inorganica Chimica Acta, 2011
Isomers of dichlorobis(2-phenylazopyridine)ruthenium(II) [Ru(azpy) 2 Cl 2 ], especially the so-called a isomer, display remarkably high cytotoxicities against human tumor cell lines. Unfortunately, the parent [Ru(azpy) 2 Cl 2 ] compounds are poorly water-soluble. In this paper the synthesis and characterization of the new water-soluble ligand 2-phenylazopyridine-5-sulfonic acid (Hsazpy) is described. Use of this ligand in reaction with RuCl 3 gave two isomers, which were isolated as aand b-[NEt 4 ] 2 [Ru(sazpy) 2 Cl 2 ]. The compounds have been fully characterized by (2D) NMR spectroscopy. The molecular structure of the a isomer of [NEt 4 ] 2 [Ru(sazpy) 2 Cl 2 ]Á2H 2 O has been determined by single-crystal structure analysis. The packing in the crystal structure of a-[NEt 4 ] 2 [Ru(sazpy) 2 Cl 2 ]Á2H 2 O shows an interesting hydrogen-bonding pattern in which two water molecules are involved. One water molecule bridges between a Cl ligand and a SO 3 À group within one ruthenium moiety, the other water molecule forms a bridge between two SO 3 À groups from two different ruthenium centers, resulting in a chain-like structure. Preliminary evaluation of the cytotoxicity by means of the IC 50 value in A2780 cell line classifies a-[NEt 4 ] 2 [Ru(sazpy) 2 Cl 2 ] as non-toxic, but this does not rule out other anticancer activities.
European Journal of Inorganic Chemistry, 2018
A series of cationic [Ru(L)(PPh3)2Cl] + (1-3) and neutral [Ru(L)(PPh3)Cl2] (4-6) Ru(II) complexes have been synthesized by reacting [RuCl2(PPh3)2] with 4'-(aryl)-2,2':6',2''-terpyridyl based ligands (L1-L3) by varying the aryl groups (tolyl, phenyl and 4fluorophenyl). The synthesized Ru(II) complexes have been unambiguously characterized by various spectroscopic tools such as FTIR and multinuclear NMR as well as HRMS analyses. The neutral complexes (4-6) have also been structurally characterized by single crystal X-ray diffraction studies. Photophysical and electrochemical studies of the Ru(II) complexes have been carried out to understand the substituent effect of the 4′-aryl group of the ligands L1-L3. These Ru(II) complexes show good catalytic activity in transfer hydrogenation (TH) of ketones with a wide substrates scope in refluxing isopropanol. Optimization study reveals that the neutral Ru(II) complexes act as better catalysts over cationic Ru(II) complexes for TH reactions. Finally, [Ru(L1)(PPh3)2H] + (7) having [Ru(II)-H] functionality has been successfully synthesized, isolated and proposed as the catalytically active species. The controlled experiment by [Ru(II)-H] complex in the absence of base has been carried out to establish the mechanism of catalytic TH of ketones.
Polyhedron, 2013
The novel trans-[RuCl 2 (dpme)(L)] complexes (1L 1-1L 4) {dpme is H 2 C@C(CH 2 PPh 2) 2 and L is 1,2-ethanediamine (L 1), 1,3-propanediamine (L 2), 2,2-dimethyl-1,3-propanediamine (L 3) and 1,4-butanediamine (L 4)} were obtained by reacting trans-[RuCl2(dpme) 2 ] with an excess amount of the corresponding diamine in CH 2 Cl 2 as the solvent. One of the diphosphine ligands was quantitatively replaced by the corresponding diamine, even when excess diamine was added. In solution the trans-[RuCl 2 (dpme)(diamine)] isomer configuration was confirmed by NMR spectroscopy and the X-ray crystal structure of 1L 2 was also determined. These diphosphine complexes (1L 1-1L 4) have exhibited significant activity and selectivity as hydrogenation catalysts for a,b-unsaturated ketones. Increasing the chelating ring of the diamine ligands from five and six to seven decreases the turnover frequencies (TOFs). The catalytic activities were compared to the analogous trans-[RuCl 2 (dppp)(L)] (2L 1-2L 4) {dppp is H 2 C(CH 2 PPh 2) 2 }. Complexes 1L 1-1L 4 catalyzed the hydrogenation of a,b-unsaturated ketones faster than the previously reported complexes 2L 1-2L 4. Density functional theory (DFT) calculations have been carried out to study the shift in the Ru(III)/Ru(II) couple and the catalytic activity for two representative complexes, 1L 2 and 2L 2 .