1737-26-4Relevant articles and documents
Asymmetric hydrogenation of aromatic ketones catalyzed by (1S,2S)-DPEN-modified Ru-PPh3/γ-Al2O3 catalyst
Tang, Bo,Xiong, Wei,Liu, De-Rong,Jia, Yun,Wang, Jin-Bo,Chen, Hua,Li, Xian-Jun
, p. 1397 - 1401 (2008)
The asymmetric hydrogenations of acetophenone and its derivatives over the (1S,2S)-DPEN-modified Ru-PPh3/γ-Al2O3 were investigated. The effects of reaction conditions on the asymmetric hydrogenation of acetophenone are dis
Hydrogenation of aryl ketones using palladium nanoparticles on single-walled carbon nanotubes in an ionic liquid
Lee, Jae Kwan,Kim, Mahn-Joo
, p. 499 - 501 (2011)
Single-walled carbon nanotubes (SWNTs) are used as supporting materials for palladium (Pd) nanoparticles generated in situ in ionic liquid (IL); Pd nanocatalysts on SWNTs exhibit superior reactivity for hydrogenation of aryl ketones in IL under mild conditions (1 atm of H2 (g) and room temperature) and can be reused above 10 times without any loss of catalytic activity.
N-heterocyclic carbenes of iridium(I): Ligand effects on the catalytic activity in transfer hydrogenation
Zinner, Sandra C.,Rentzsch, Christoph F.,Herdtweck, Eberhardt,Herrmann, Wolfgang A.,Kuehn, Fritz. E.
, p. 7055 - 7062 (2009)
New Ir-NHC complexes based on different heterocyclic moieties like imidazole, benzimidazole and imidazolidine are presented and tested in transfer hydrogenation catalysis. A broad range of steric and electronic properties of NHC ligands is covered to give an idea for catalyst design from the experimental point of view.
Highly electron-rich pincer-type iron complexes bearing innocent bis(metallylene)pyridine ligands: Syntheses, structures, and catalytic activity
Gallego, Daniel,Inoue, Shigeyoshi,Blom, Burgert,Driess, Matthias
, p. 6885 - 6897 (2014)
The first neutral bis(metallylene)pyridine pincer-type [ENE] ligands (E = SiII, GeII) were synthesized, and their coordination chemistry and reactivity toward iron was studied. First, the unprecedented four-coordinate complexes κ2E,E'-[ENE]FeCl2 were isolated. Unexpectedly and in contrast to other related pyridine-based pincer-type Fe(II) complexes, the N atom of pyridine is reluctant to coordinate to the Fe(II) site due to the enhanced α-donor strength of the E atoms, which disfavors this coordination mode. Subsequent reduction of κ2Si,Si'-[SiNSi]FeCl2 with KC8 in the presence of PMe3 or direct reaction of the [ENE] ligands using Fe(PMe3)4 produced the highly electron-rich iron(0) complexes [ENE]Fe(PMe3)2. The reduction of the iron center substantially changes its coordination features, as shown by the results of a single-crystal X-ray diffraction analysis of [SiNSi]Fe(PMe3)2. The iron center, in the latter, exhibits a pseudosquare pyramidal (PSQP) coordination environment, with a coordinative (pyridine)-Rfnet→Fe bond, and a trimethylphosphine ligand occupying the apical position. This geometry is very unusual for Fe(0) low-spin complexes, and variable-temperature 1H and 31P NMR spectra of the [ENE]Fe(PMe3)2 complexes revealed that they represent the first examples of configurationally stable PSQP-coordinated Fe(0) complexes: even after heating at 70 °C for >7 days, no changes are observed. The substitution reaction of [ENE]Fe(PMe3)2 with CO resulted in the isolation of [ENE]Fe(CO)2 and the hitherto unknown κ2E,E'-[ENE]Fe(CO)2L (L = CO, PMe3) complexes. All complexes were fully characterized (NMR, MS, XRD, IR, and 57Fe M?ssbauer spectroscopy), showing the highest electron density on the iron center for pincer-type complexes reported to date. DFT calculations and 57Fe M?ssbauer spectroscopy confirmed the innocent behavior of these ligands. Moreover, preliminary results showed that these complexes can serve as active precatalysts for the hydrosilylation of ketones.
DYNAMIC KINETIC RESOLUTION OF ALCOHOLS BY ENANTIOSELECTIVE SILYLATION
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Page/Page column 38; 41-42, (2022/04/16)
The invention relates to non-enzymatic dynamic kinetic resolution (DKR) process for enantioselective silylation of a chiral alcohol, the process comprising reacting a substrate comprising a first enantiomer of the chiral alcohol using a racemization catalyst, and generating from said second enantiomer and a hydrosilane a silyl ether using an enantioselective silylation catalyst, wherein the enantioselective silylation catalyst is a catalytic system comprising a copper salt, an inorganic or organometallic base and (-)-1,2-bis((2R,5R)-2,5-diarylphospholano)ethane or (+)-1,2-bis((2S,5S)-2,5-diarylphospholano)ethane ((R,R)-Ar-BPE or (S,S)-Ar-BPE), and the racemization catalyst is a compound according to Formula I as disclosed herein.
Hydrosilylation of Aldehydes and Ketones Catalyzed by a 2-Iminopyrrolyl Alkyl-Manganese(II) Complex
Cruz, Tiago F. C.,Veiros, Luís F.,Gomes, Pedro T.
supporting information, p. 1195 - 1206 (2022/01/11)
A well-defined and very active single-component manganese(II) catalyst system for the hydrosilylation of aldehydes and ketones is presented. First, the reaction of 5-(2,4,6-iPr3C6H2)-2-[N-(2,6-iPr2C6H3)formimino]pyrrolyl potassium (KL) and [MnCl2(Py)2] afforded the binuclear 2-iminopyrrolyl manganese(II) pyridine chloride complex [Mn2{κ2N,N′-5-(2,4,6-iPr3C6H2)-NC4H2-2-C(H)═N(2,6-iPr2C6H3)}2(Py)2(μ-Cl)2] 1. Subsequently, the alkylation reaction of complex 1 with LiCH2SiMe3 afforded the respective (trimethylsilyl)methyl-Mn(II) complex [Mn{κ2N,N′-5-(2,4,6-iPr3C6H2)-NC4H2-2-C(H)═N(2,6-iPr2C6H3)}(Py)CH2SiMe3] 2 in a good yield. Complexes 1 and 2 were characterized by elemental analysis, 1H NMR spectroscopy, Evans' method, FTIR spectroscopy, and single-crystal X-ray diffraction. While the crystal structure of complex 1 has been identified as a binuclear entity, in which the Mn(II) centers present pentacoordinate coordination spheres, that of complex 2 corresponds to a monomer with a distorted tetrahedral coordination geometry. Complex 2 proved to be a very active precatalyst for the atom-economic hydrosilylation of several aldehydes and ketones under very mild conditions, with a maximum turnover frequency of 95 min-1, via a silyl-Mn(II) mechanistic route, as asserted by a combination of experimental and theoretical efforts, the respective silanes were cleanly converted to the respective alcoholic products in high yields.
Ambient-pressure highly active hydrogenation of ketones and aldehydes catalyzed by a metal-ligand bifunctional iridium catalyst under base-free conditions in water
Wang, Rongzhou,Yue, Yuancheng,Qi, Jipeng,Liu, Shiyuan,Song, Ao,Zhuo, Shuping,Xing, Ling-Bao
, p. 1 - 7 (2021/05/17)
A green, efficient, and high active catalytic system for the hydrogenation of ketones and aldehydes to produce corresponding alcohols under atmospheric-pressure H2 gas and ambient temperature conditions was developed by a water-soluble metal–ligand bifunctional catalyst [Cp*Ir(2,2′-bpyO)(OH)][Na] in water without addition of a base. The catalyst exhibited high activity for the hydrogenation of ketones and aldehydes. Furthermore, it was worth noting that many readily reducible or labile functional groups in the same molecule, such as cyan, nitro, and ester groups, remained unchanged. Interestingly, the unsaturated aldehydes can be also selectively hydrogenated to give corresponding unsaturated alcohols with remaining C=C bond in good yields. In addition, this reaction could be extended to gram levels and has a large potential of wide application in future industrial.
