55100-76-0Relevant academic research and scientific papers
Flat and Efficient H CNN and CNN Pincer Ruthenium Catalysts for Carbonyl Compound Reduction
Giboulot, Steven,Baldino, Salvatore,Ballico, Maurizio,Figliolia, Rosario,P?thig, Alexander,Zhang, Shuanming,Zuccaccia, Daniele,Baratta, Walter
supporting information, p. 1127 - 1142 (2019/03/14)
The bidentate HCNN dicarbonyl ruthenium complexes trans,cis-[RuCl2(HCNN)(CO)2] (1-3) and trans,cis-[RuCl2(ampy)(CO)2] (1a) were prepared by reaction of [RuCl2(CO)2]n with 1-[6-(4′-methylphenyl)pyridin-2-yl]methanamine, benzo[h]quinoline (HCNN), and 2-(aminomethyl)pyridine (ampy) ligands. Alternatively, the derivatives 1-3 were obtained from the reaction of RuCl3 hydrate with HCO2H and HCNN. The pincer CNN cis-[RuCl(CNN)(CO)2] (4) was isolated from 1 by reaction with NEt3. The monocarbonyl complexes trans-[RuCl2(HCNN)(PPh3)(CO)] (5-7) were synthesized from [RuCl2(dmf)(PPh3)2(CO)] and HCNN ligands, while the diacetate trans-[Ru(OAc)2(HCNN)(PPh3)(CO)] (8) was obtained from [Ru(OAc)2(PPh3)2(CO)]. Carbonylation of cis-[RuCl(CNN)(PPh3)2] with CO afforded the pincer derivatives [RuCl(CNN)(PPh3)(CO)] (9-11). Treatment of 9 with Na[BArf]4 and PPh3 gave the cationic complex trans-[Ru(CNN)(PPh3)2(CO)][BArf4] (12). The dicarbonyl derivatives 1-4, in the presence of PPh3 or PCy3, and the monocarbonyl complexes 5-12 catalyzed the transfer hydrogenation (TH) of acetophenone (a) in 2-propanol at reflux (S/C = 1000-100000 and TOF up to 100000 h-1). Compounds 1-3, with PCy3, and 6 and 8-10 were proven to catalyze the TH of carbonyl compounds, including α,β-unsaturated aldehydes and bulky ketones (S/C and TOF up to 10000 and 100000 h-1, respectively). The derivatives 1-3 with PCy3 and 5 and 6 catalyzed the hydrogenation (HY) of a (H2, 30 bar) at 70 °C (S/C = 2000-10000). Complex 5 was active in the HY of diaryl ketones and aryl methyl ketones, leading to complete conversion at S/C = 10000.
Reactions of Grubbs catalysts with excess methoxide: Formation of novel methoxyhydride complexes
Beach, Nicholas J.,Lummiss, Justin A. M.,Bates, Jennifer M.,Fogg, Deryn E.
, p. 2349 - 2356 (2012/06/04)
On exposure to NaOMe (≥3 equiv) in CH2Cl2-MeOH at 23 °C, the first-generation Grubbs catalyst RuCl2(PCy 3)2(=CHPh) (1a) is immediately transformed into the six-coordinate methoxyhydride complexes RuH(OMe)(CO)2(PCy 3)2 (4a) and RuH(OMe)(CO)(H2)(PCy 3)2 (5a). Complex 5a can be recycled into 4a under conditions conducive to removal of H2. The second-generation catalyst RuCl2(IMes)(PCy3)(=CHPh) (1b; IMes = N,N′- bis(mesityl)imidazol-2-ylidene) reacts more slowly, requiring several hours even at 20 equiv of NaOMe, and terminates at five-coordinate RuH(OMe)(CO)(IMes) (PCy3) (3b). Experiments in the presence of added PCy3 reveal that consumption of 1a, but not 1b, proceeds via the four-coordinate intermediate formed by equilibrium loss of phosphine, a function of the lability of the PCy3 ligand at ambient temperatures. The poor accessibility of such an intermediate for 1b at 23 °C retards salt metathesis and inhibits further reaction of 3b. For the bis(PCy3) analogue 3a, fast transformation into 4a is proposed to involve reversible loss of PCy 3, coordination of methanol, σ-metathesis of methanol at the hydride site to liberate H2, and β-elimination/decarbonylation of bound methoxide. Competitive uptake of H2 by 3a yields six-coordinate 5a (the dihydrogen adduct of 3a). Independent routes to RuH(OMe)(CO)2(L)(PCy3) (4a/b; a, L = PCy3; b, L = IMes) were developed: these involved sequential transformation of RuHCl(CO)(L)(PCy3) (2a/b) into the bis-carbonyl adducts RuHCl(CO)2(L)(PCy3) (7a/b) under CO, conversion of 7a/b into the more reactive triflates RuH(OTf)(CO)2(L)(PCy3) (8a/b), and reaction of 8a/b with equimolar NaOMe. Dihydride 6b was also prepared, by reaction of 8b with NaH.
Synthesis and characterization of some ruthenium-phosphoniodithiocarboxylate complexes
Gaffney, Thomas R.,Ibers, James A.
, p. 2062 - 2064 (2008/10/08)
Addition of CS2 to RuClH(CO)(PCy3)2 affords the cation [RuH(CO)(S2CPCy3)(PCy3)2] +, which has been isolated as the tetraphenylborate salt. The closely related complex [RuCl(CO)(S2CPCy3)(PCy3)2][BPh 4] is formed when the zwitterion ligand S2CPCy3 is added to a methanol suspension of RuCl2(CO)(PCy3)2 and NaBPh4. The reaction of carbonyl sulfide with RuClH(CO)(PCy3)2 results in the formation of RuClH(CO)2(PCy3)2.
