33673-65-3Relevant academic research and scientific papers
Ru(0) and Ru(II) nitrosyl pincer complexes: Structure, reactivity, and catalytic activity
Fogler, Eran,Iron, Mark A.,Zhang, Jing,Ben-David, Yehoshoa,Diskin-Posner, Yael,Leitus, Gregory,Shimon, Linda J. W.,Milstein, David
, p. 11469 - 11479 (2013)
Despite considerable interest in ruthenium carbonyl pincer complexes and their substantial catalytic activity, there has been relatively little study of the isoelectronic ruthenium nitrosyl complexes. Here we describe the synthesis and reactivity of several complexes of this type as well as the catalytic activity of complex 6. Reaction of the PNP ligand (PNP = 2,6-bis( tBu2PCH2)pyridine) with RuCl 3(NO)(PPh3)2 yielded the Ru(II) complex 3. Chloride displacement by BArF- (BArF- = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) gave the crystallographicaly characterized, linear NO Ru(II) complex 4, which upon treatment with NaBEt 3H yielded the Ru(0) complexes 5. The crystallographically characterized Ru(0) square planar complex 5·BF4 bears a linear NO ligand located trans to the pyridilic nitrogen. Further treatment of 5·BF4 with excess LiOH gave the crystallographicaly characterized Ru(0) square planar, linear NO complex 6. Complex 6 catalyzes the dehydrogenative coupling of alcohols to esters, reaching full conversion under air or under argon. Reaction of the PNN ligand (PNN = 2-(tBu 2PCH2)-6-(Et2NCH2)pyridine) with RuCl3(NO)(H2O)2 in ethanol gave an equilibrium mixture of isomers 7a and 7b. Further treatment of 7a + 7b with 2 equivalent of sodium isopropoxide gave the crystallographicaly characterized, bent-nitrosyl, square pyramidal Ru(II) complex 8. Complex 8 was also synthesized by reaction of PNN with RuCl3(NO)(H2O)2 and Et3N in ethanol. Reaction of the "long arm" PN2N ligand (PN 2N = 2-(tBu2PCH2-)-6-(Et 2NCH2CH2)pyridine) with RuCl 3(NO)(H2O)2 in ethanol gave complex 9, which upon treatment with 2 equiv of sodium isopropoxide gave complex 10. Complex 10 was also synthesized directly by reaction of PN2N with RuCl 3(NO)(H2O)2 and a base in ethanol. A noteworthy aspect of these nitrosyl complexes is their preference for the Ru(0) oxidization state over Ru(II). This preference is observed with both aromatized and dearomatized pincer ligands, in contrast to the Ru(II) oxidation state which is preferred by the analogous carbonyl complexes.
Acetals from primary alcohols with the use of tridentate proton responsive phosphinepyridonate iridium catalysts
Sahoo,Jiang,Bruneau,Sharma,Suresh,Achard
, p. 100554 - 100558 (2016/11/09)
The association of the new phosphinepyridonate ligands along with an iridium metallic precursor resulted in the selective acetalization of various primary alcohols via a formal dehydrogenative coupling reaction.
The levels of fatty alcohol dehydrogenation coupling method for preparing aldehyde-acetal
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Paragraph 0033; 0034, (2016/10/08)
The invention discloses a method for preparing acetal by dehydrogenation coupling of first-stage fatty alcohol. The method comprises the following steps: adding alcohol reaction liquid to commercial titanium dioxide P25, and simultaneously adding a precious metals source solution; vacuumizing or introducing argon under magnetic agitation; stopping vacuumizing or introducing argon after oxygen in the system is removed; turning on an ultraviolet light source; reducing a precious metal source into precious metal particles by in-situ photocatalysis, and loading to the titanium dioxide surface; carrying out dehydrogenation coupling on catalyzed alcohol to form the acetal; controlling the reaction temperature at 10-70 DEG C and the reaction time at 10-72 hours; separating a catalyst through centrifugal participation, vacuum filtration or static precipitation after the reaction is ended, and then carrying out reduced pressure distillation to remove alcohol, so as to obtain the acetal product. The method has the advantages of high selectivity, high yield, low cost and the like, and is environmental friendly, and the purity can be up to over 97%.
TiO2-photocatalytic acceptorless dehydrogenation coupling of primary alkyl alcohols into acetals
Zhang, Hongxia,Zhu, Zhenping,Wu, Yupeng,Zhao, Tianjian,Li, Li
, p. 4076 - 4080 (2014/10/15)
Primary alkyl alcohols can be directly converted into acetals and H 2via TiO2-photocatalytic dehydrogenation coupling at room temperature, with no need for any hydrogen acceptors. The reaction follows a tandem process integrating photocatalytic alcohol dehydrogenation and H +-catalytic acetalation, in which the H+ ion catalysts are provided by the alcohol dehydrogenation in real time. This approach exhibits a very high reaction rate and product selectivity, and represents a novel green process for the conversion of primary alkyl alcohols, especially for bio-renewable ethanol and 1-butanol. the Partner Organisations 2014.
Selective acceptorless conversion of primary alcohols to acetals and dihydrogen catalyzed by the ruthenium(II) complex Ru(PPh3) 2(NCCH3)2(SO4)
Kossoy, Elizaveta,Diskin-Posner, Yael,Leitus, Gregory,Milstein, David
experimental part, p. 497 - 504 (2012/04/23)
The complex bis(acetonitrile)bis(triphenylphosphine)ruthenium(II) sulfate [Ru(PPh3)2(NCCH3)2(SO4)], fully characterized spectroscopically and by a single crystal X-ray study, catalyzes at 110 °C the direct transformation of primary alcohols to the corresponding acetals with liberation of molecular hydrogen. The formation of acetals proceeds via direct substitution of the hydroxy group of the hemiacetal intermediate by an alcohol molecule. The closely related bis(triphenylphosphine) ruthenium(II) acetate [Ru(PPh3)2(OAc)2] catalyzes the conversion of primary alcohols to the corresponding esters rather than acetals. Copyright
Method for producing enol ethers
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, (2008/06/13)
Enol ethers of the formula I where R1is an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radical which may carry further substituents which do not react with acetylenes or allenes, and the radicals R, independently of one another, are hydrogen or aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radicals, which may be bonded to one another to form a ring, and m is 0 or 1, are prepared by reacting an acetal or ketal of the formula II with an acetylene or allene of the formula III or IV where R and R1have the abovementioned meanings, in the gas phase at elevated temperatures in the presence of a zinc- or cadmium- and silicon- and oxygen-containing heterogeneous catalyst.
Ruthenium-Catalyzed Oxidative Transformation of Alcohols and Aldehydes to Esters and Lactones
Murahashi, Shun-Ichi,Naota, Takeshi,Ito, Keiichiro,Maeda, Yoshihiro,Taki, Hiroshi
, p. 4319 - 4327 (2007/10/02)
Primary alcohols undergo oxidative condensation upon treatment with RuH2(PPh3)4 catalyst to give esters and molecular hydrogen.Similarly, 1,4- and 1,5-diols can be converted into the corresponding γ- and δ-lactones, respectively.The lactonization is greatly enhanced by accepting hydrogen with an appropriate hydrogen acceptor such as acetone.Primary alcohols are oxidized chemoselectively in the presence of secondary alcohols to give the corresponding lactones.These reactions are operationally simple and highly efficient for synthesis of esters and lactones from alcohols.The principle of the oxidative condensation of alcohols can be extended to ester formation from aldehydes and alcohols.The ruthenium-catalyzed reaction of aldehydes with water gives esters, while the same reaction in the presence of a hydrogen acceptor gives carboxylic acids.The key step of these reactions is the oxidative addition of ruthenium into the OH bonds of alcohols and subsequent β-elimination of (RuH) species to give the corresponding carbonyl compounds.
