40935-25-9Relevant academic research and scientific papers
Insights into the decomposition of olefin metathesis precatalysts
Manzini, Simone,Poater, Albert,Nelson, David J.,Cavallo, Luigi,Slawin, Alexandra M. Z.,Nolan, Steven P.
supporting information, p. 8995 - 8999 (2014/12/10)
The decomposition of a series of benzylidene, methylidene, and 3-phenylindenylidene complexes has been probed in alcohol solution in the presence of base. Tricyclohexylphosphane-containing precatalysts are shown to yield [RuCl(H)(H2)(PCy3)2] in isopropyl alcohol solutions, while 3-phenylindenylidene complexes lead to η5-(3- phenyl)indenyl products. The potential-energy surfaces for the formation of the latter species have been probed using density functional theory studies.
From ruthenium olefin metathesis catalyst to (η5-3- phenylindenyl)hydrido complex via alcoholysis
Manzini, Simone,Nelson, David J.,Lebl, Tomas,Poater, Albert,Cavallo, Luigi,Slawin, Alexandra M. Z.,Nolan, Steven P.
supporting information, p. 2205 - 2207 (2014/02/14)
The synthesis and characterisation of [Ru(H)(η5-3- phenylindenyl)(iBu-Phoban)2] 4 is reported ( iBu-Phoban = 9-isobutyl-9-phosphabicyclo-[3.3.1]-nonane). 4 is obtained via alcoholysis of metathesis pre-catalyst M11, in a process that was previously thought to be limited to analogous complex [RuCl 2(PPh3)2(3-phenylindenylidene)] (M 10). The Royal Society of Chemistry.
Hydrogenolysis versus methanolysis of first-and second-generation grubbs catalysts: Rates, speciation, and implications for tandem catalysis
Beach, Nicholas J.,Camm, Kenneth D.,Fogg, Deryn E.
, p. 5450 - 5455 (2010/12/24)
An unexpected "generation gap" is uncovered between the Grubbs catalysts RuCl2(L)(PCy3)(=CHPh) (1a, L = PCy3; 1b, L = IMes, N,N′-bis(mesityl)imidazol-2-ylidene) in their reactions with hydrogen versus methanol, in the pres
Multifaceted chemistry of [(Cymene)RuCl2]2 and PCy3
Solari, Euro,Gauthier, Sebastien,Scopelliti, Rosario,Severin, Kay
, p. 4519 - 4526 (2009/12/06)
The reaction of [(cymene)RuCl2]2 (1) with PCy 3 was investigated using different stoichiometries and reaction conditions. Whereas a mixture of complex 1 and 2 equiv of PCy3 in methanol gave the known adduct [(cy
New catalytic route to borasiloxanes
Marciniec, Bogdan,Walkowiak, Jedrzej
scheme or table, p. 2695 - 2697 (2009/02/05)
A new, highly selective method for effective synthesis of boryl silyl ethers (borasiloxanes) via O-borylation of silanols with vinylboronates catalyzed by the Ru-H complexes [RuHCl(CO)(PCy3)2] and [RuHCl(CO)(PPh3)3/s
Understanding structural isomerization during ruthenium-catalyzed olefin metathesis: A deuterium labeling study
Courchay, Florence C.,Sworen, John C.,Ghiviriga, Ion,Abboud, Khalil A.,Wagener, Kenneth B.
, p. 6074 - 6086 (2008/10/09)
A deuterium labeling study was undertaken to determine the mechanism of olefin isomerization during the metathesis reactions catalyzed by a second-generation Grubbs catalyst (2). The reaction of allyl-1,1-d2 methyl ether with 2 at 35°C was followed by 1H and 2H NMR spectroscopy. The evidence of deuterium incorporation at the C-2 position of the isomerized product, trans-propenyl methyl ether, led to the conclusion that a metal hydride addition - elimination mechanism was operating under these conditions. Consequently, complex 8, an analogue of 2 bearing deuterated o-methyl groups on the aromatic rings of the NHC ligand, was synthesized to investigate the role of the NHC ligand in the formation of hydride species. Thermal decomposition of benzylidene 8 and methylidene 8′ was monitored by 2H NMR spectroscopy; no deuteride complex was detected in either case. The decomposition mixtures were tested for isomerization activity with benchmark 1-octene but did not match the isomerization rates observed with 2 under similar metathesis conditions. Reaction of complex 8 with various olefmic substrates not only confirmed the formation of a deuteride complex but also revealed the existence of a competitive H/D exchange process between the CD 3 groups on the NHC ligand and the C-H bonds of the substrate. We propose that the exchange is promoted by a ruthenium dihydride intermediate whose formation is closely related to the methylidene decomposition.
New catalytic route to functionalized vinylboronates
Marciniec, Bogdan,Jankowska, Magdalena,Pietraszuk, Cezary
, p. 663 - 665 (2007/10/03)
Vinylsubstituted boronates i.e. vinyldioxaborolane and vinyldioxaborinane react regioselectively with olefins in the presence of RuHCl(CO)(PCy 3)2 with the formation of functionalized vinylboron derivatives. The reaction opens a new catalytic route for preparation of organoboranes. The Royal Society of Chemistry 2005.
Degradation of the second-generation Grubbs metathesis catalyst with primary alcohols and oxygen - Isomerization and hydrogenation activities of monocarbonyl complexes
Dinger, Maarten B.,Mol, Johannes C.
, p. 2827 - 2833 (2007/10/03)
Reaction of the second-generation Grubbs metathesis catalyst [RuCl 2(=CHPh)(H2IMes)(PCy3)] (2) (H2IMes = 1,3-dimethyl-4,5-dihydroimidazol-2-ylidene) with primary alcohols in the presence of a base produced the complexes [RuClH(CO)(PCy3) 2] (3) and [RuClH(CO)(H2IMes)(PCy3)] (5). When benzyl alcohol was used, the ruthenium phenyl complexes [RuClPh(CO)(PCy 3)2] (4) and [RuClPh(CO)(H2IMes)(PCy 3)] (7) were formed in addition to 3 and 5. Complex 7, characterised by an X-ray structure analysis, was also formed on exposure of 2 to oxygen. The isomerization and hydrogenation activity of 7 was determined and compared with that of 3 and 4. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
Degradation of the first-generation Grubbs metathesis catalyst with primary alcohols, water, and oxygen. Formation and catalytic activity of ruthenium(II) monocarbonyl species
Dinger, Maarten B.,Mol, Johannes C.
, p. 1089 - 1095 (2008/10/08)
The first-generation Grubbs metathesis catalyst (PCy3)22Ru(=CHPh)(Cl)2 (1) was reacted with primary alcohols at 70 °C to give the monohydride species (PCy3)2(CO)Ru(Cl)(H) (4) in ～20% yield. Addition of either an inorganic or organic base greatly facilitated the formation of the hydride, and 4 could be isolated in >70% yield in the case of 1-propanol and triethylamine. Analysis of the reaction products and labeling experiments revealed that 4 was formed via a noncatalytic alcohol dehydrogenation pathway. When benzyl alcohol was used, (PCy3)2(CO)Ru(Cl)(Ph) (5) was formed, this also being one of the products of the decomposition of 1 by oxygen in both solid and solution states. Complexes 4 and 5 were found to be active and selective alkene double-bond isomerization catalysts.
Synthesis and activity of ruthenium alkylidene complexes coordinated with phosphine and N-heterocyclic carbene ligands
Trnka, Tina M.,Morgan, John P.,Sanford, Melanie S.,Wilhelm, Thomas E.,Scholl, Matthias,Choi, Tae-Lim,Ding, Sheng,Day, Michael W.,Grubbs, Robert H.
, p. 2546 - 2558 (2007/10/03)
This paper reports the synthesis and characterization of a variety of ruthenium complexes coordinated with phosphine and N-heterocyclic carbene (NHC) ligands. These complexes include several alkylidene derivatives of the general formula (NHC)(PR3)(Cl)2Ru=CHR′, which are highly active olefin metathesis catalysts. Although these catalysts can be prepared adequately by the reaction of bis(phosphine) ruthenium alkylidene precursors with free NHCs, we have developed an alternative route that employs NHC-alcohol or -chloroform adducts as "protected" forms of the NHC ligands. This route is advantageous because NHC adducts are easier to handle than their free carbene counterparts. We also demonstrate that sterically bulky bis(NHC) complexes can be made by reaction of the pyridine-coordinated precursor (NHC)(py)2(Cl)2Ru=CHPh with free NHCs or NHC adducts. Two crystal structures are presented, one of the mixed bis(NHC) derivative (H2IMes)(IMes)(Cl)2Ru=CHPh, and the other of (PCy3)(Cl)(CO)Ru[η2-(CH2- C6H2Me2)(N2 C3H4)(C6H2Me3)], the product of ortho methyl C-H bond activation. Other side reactions encountered during the synthesis of new ruthenium alkylidene complexes include the formation of hydridocarbonyl-chloride derivatives in the presence of primary alcohols and the deprotonation of ruthenium vinylcarbene ligands by KOBut. We also evaluate the olefin metathesis activity of NHC-coordinated complexes in representative RCM and ROMP reactions.
