1749-19-5Relevant articles and documents
Mechanism of elimination from (1-anilino-1-cyanoethyl)benzene promoted by sodium methoxide in methanol
Cho, Bong Rae,Oh, Yoon Chul,Lee, Sang Hae,Park, Young Ja
, p. 5656 - 5658 (1996)
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Sisti
, p. 1272 (1968)
Chemoselective Reduction of Imines Catalyzed by Ruthenium(II) Half-Sandwich Complexes: A Mechanistic Study
Reshi, Noor U. Din,Kathuria, Lakshay,Samuelson, Ashoka G.
, p. 2947 - 2955 (2019)
Ruthenium half-sandwich complexes ligated to chiral 2-oxazolidinethiones or 2-thiozolidinethiones in the reduction of N-benzylideneaniline using silyl hydrides as reductants has been examined. The chemoselective reduction of imines takes place under mild conditions to afford the corresponding amines in nearly quantitative yield. Mechanistic studies indicate that dissociation of the ancillary ligands generate the active catalyst in all the complexes studied, which is the same species generated by [Ru(p-cymene)(Cl)2]2 under the reaction conditions. This results in the formation of a single catalytic species irrespective of the starting half-sandwich complex. Detailed mechanistic studies involving trapping of intermediates, in situ studies using mass spectrometry and NMR spectroscopy were carried out using the active catalyst generated by [Ru(p-cymene)(Cl)2]2. The mechanism of the reaction is dependent on the number of the hydrogen atoms in the reducing silane. The reaction proceeds via Gade-Hoffman pathway or Zheng-Chan pathway when a dihydro or trihydrosilane is the reductant. However, the use of a monohydrosilane, leads to longer reaction times presumably due to a change in the reaction pathway.
Highly efficient and enantioselective iridium-catalyzed asymmetric hydrogenation of N-arylimines
Li, Wei,Hou, Guohua,Chang, Mingxin,Zhang, Xumu
, p. 3123 - 3127 (2009)
A catalytic method employing the cationic iridium-(Sc,R p)-DuanPhos [(1R,1'R,2S,2'S)-2,2'-ditert-butyl-2,2',3,3'-tetrahydro- 1H,1'H-1,1'-biisophosphindole] complex and BARF {tetrakis[3,5- bis(trifluoromethyl)phenyl]borate} counterion
Understanding the Synergistic Effects Observed When Using Tethered Dual Catalysts for Heat and Light Activated Catalysis
Wang, Danfeng,Pernik, Indrek,Keaveney, Sinead T.,Messerle, Barbara A.
, p. 5091 - 5097 (2020)
Dual catalysis, where two different catalysts work cooperatively to promote a chemical reaction, is an important synthetic approach as it can allow a wide range of unique reactivity to be accessed. Whilst most dual catalysis strategies utilise separate ca
Heterogeneous catalysts for hydroamination reactions: Structure-activity relationship
Penzien, Jochen,Haessner, Carmen,Jentys, Andreas,Koehler, Klaus,Mueller, Thomas E.,Lercher, Johannes A.
, p. 302 - 312 (2004)
The catalytic activity of ion-exchanged zeolite BEA for hydroamination reactions, such as the cyclization of 6-aminohex-1-yne and 3-aminopropylvinyl ether and the intermolecular addition of aniline to phenylacetylene, was studied. The most active catalyst
Zirconium-mediated metathesis of imines: A study of the scope, longevity, and mechanism of a complicated catalytic system
Zuckerman, Rebecca L.,Krska, Shane W.,Bergman, Robert G.
, p. 751 - 761 (2000)
By kinetically stabilizing imidozirconocene complexes through the use of a sterically demanding ligand, or by generating a more thermodynamically stable resting state with addition of diphenylacetylene, we have developed transition metal-catalyzed imine metathesis reactions that are mechanistically analogous to olefin metathesis reactions catalyzed by metal carbene complexes. When 5 mol% of Cp*Cp(THF)Zr = N'Bu is used as the catalyst precursor in the metathesis reaction between PhCH = NPh and p-TolCH = N-p-Tol, a 1:1:1:1 equilibrium mixture with the two mixed imines p-TolCH = NPh and PhCH = N-p-Tol is generated in C6D6 at 105 °C. The catalyst was still active after 20 days with an estimated 847 turnovers (t(1/2) 170 m; TON = 1.77 h-1). When the azametallacyclobutene Cp2Zr(N(Tol)C(Ph) = C(Ph)) is used as the catalyst precursor under similar reaction conditions, a total of 410 turnovers are obtained after 4 days (t(1/2) 170 m; TON = 4.3 h-1). An extensive kinetic and equilibrium analysis of the metallacyclobutene- catalyzed metathesis of PhCH = N-p-Tol and p-F-C6H4CH = N-p-F-C6H4 was carded out by monitoring the concentrations of imines and observable metal- containing intermediates over time. Numerical integration methods were used to fit these data to a detailed mechanism involving coordinatively unsaturated (16-electron) imido complexes as critical intermediates. Examination of the scope of reaction between different organic imines revealed characteristic selectivity that appears to be unique to the zirconium-mediated system. Several zirconocene complexes that could generate the catalytically active 'CpCp'Zr = NAr' (Cp' = Cp or Cp*) species in situ were found to be effective agents in the metathetical exchange between different N-aryl imines. N-Alkyl aldimines were found to be completely unreactive toward metathesis with N-aryl aldimines, and metathesis reactions involving the two N-alkyl imines TolCH = NPr and PhCH = NMe gave slow or erratic results, depending on the catalyst used. Metathesis was observed between N-aryl ketimines and N-aryl aldimines, but for N-aryl ketimine substrates, the catalyst resting state consists of zirconocene enamido complexes, generated by the formal C-H activation of the α position of the ketimine substrates.
Monomeric Metaphosphate Anion: Reaction with Carbonyl Groups
Satterthwait, Arnold C.,Westheimer, F. H.
, p. 1177 - 1180 (1981)
The elusive monomeric metaphosphate anion is generated rapidly at room temperature by the fragmentation of threo- or erythro- (1,2-dibromo-1-phenylpropyl)phosphonate in the presence of a hindered base; it reacts at the carbonyl groups of acetophenone and
Continuous hydroamination in a liquid-liquid two-phase system.
Neff, Volker,Mueller, Thomas E,Lercher, Johannes A
, p. 906 - 907 (2002)
The direct addition of NH across a CC multiple bond (hydroamination) was efficiently catalysed in a liquid-liquid two-phase system. The latter comprised a polar catalyst phase of Zn(CF3SO3)2 in the ionic liquid 1-ethyl-3-methylimidazolium trifuoromethanesulfonate and a substrate mixture in heptane. The possibility of catalysing different hydroamination reactions continuously was demonstrated.
Abramovitch et al.
, p. 4059 (1972)
Photoredox-Catalyzed Synthesis of α-Amino Acid Amides by Imine Carbamoylation
Cardinale, Luana,Schmotz, Mattis-Ole W. S.,Konev, Mikhail O.,Jacobi von Wangelin, Axel
supporting information, p. 506 - 510 (2022/01/20)
An operationally simple protocol for the photocatalytic carbamoylation of imines is reported. Easily available, bench-stable 4-amido Hantzsch ester derivatives serve as precursors to carbamoyl radicals that undergo rapid addition to N-aryl imines. The reaction proceeds under blue light irradiation in the presence of the photocatalyst 3DPAFIPN and Br?nsted/Lewis acid additives. Mechanistic studies indicated a photoredox mechanism that involves carbamoyl radicals.
Rational design of simple organocatalysts for the hsicl3 enantioselective reduction of (E)-n-(1-phenylethylidene)aniline
Burguete, Maria Isabel,García-Verdugo, Eduardo,Luis, Santiago V.,Maciá, María,Martí-Centelles, Vicente,Porcar, Raúl
supporting information, (2021/11/30)
Prolinamides are well-known organocatalysts for the HSiCl3 reduction of imines; however, custom design of catalysts is based on trial-and-error experiments. In this work, we have used a combination of computational calculations and experimental work, including kinetic analyses, to properly understand this process and to design optimized catalysts for the benchmark (E)-N-(1-phenylethylidene)aniline. The best results have been obtained with the amide derived from 4-meth-oxyaniline and the N-pivaloyl protected proline, for which the catalyzed process is almost 600 times faster than the uncatalyzed one. Mechanistic studies reveal that the formation of the component supramolecular complex catalyst-HSiCl3-substrate, involving hydrogen bonding breaking and costly conformational changes in the prolinamide, is an important step in the overall process.
Construction of Stable Metal–Organic Framework Platforms Embedding N-Heterocyclic Carbene Metal Complexes for Selective Catalysis
Kim, Hyunyong,Kim, Hyunseok,Kim, Kimoon,Lee, Eunsung
supporting information, p. 18687 - 18697 (2021/12/17)
We report a bottom-up approach to immobilize catalysts into MOFs, including copper halides and gold chloride in a predictable manner. Interestingly, the structures of MOFs bearing NHC metal complexes maintained a similar 4-fold interpenetrated cube. They
