27607-33-6Relevant articles and documents
A hierarchically ordered porous novel vanado-silicate catalyst for highly efficient oxidation of bulky organic molecules
Sen, Tapas,Whittle, Jacob,Howard, Matthew
, p. 4232 - 4234 (2012)
A novel hierarchically ordered porous vanado-silicate nanocomposite with interconnecting macroporous windows and meso-microporous walls containing well dispersed vanadyl species has been fabricated and used as a heterogeneous catalyst for the oxidation of a bulky organic molecule, namely cyclooctene.
Mechanistic Links in the in-situ Formation of Dinuclear Manganese Catalysts, H2O2 Disproportionation, and Alkene Oxidation
Angelone, Davide,Abdolahzadeh, Shaghayegh,De Boer, Johannes W.,Browne, Wesley R.
, p. 3532 - 3542 (2015)
The oxidation of substrates, such as alkenes, with H2O2 and the catalyst [MnIV2(μ-O)3(tmtacn)2]2+ (1; tmtacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) is promoted by the addition of carboxylic acids through the in situ formation of bis(carboxylato) complexes of the type [MnIII2(μ-O)(μ-RCO2)2(tmtacn)2]2+. The conversion of 1 to these complexes requires a complex series of redox reactions coupled with the overall exchange of μ-oxido ligands for μ-carboxylato ligands. Here, we show that the mechanism by which this conversion occurs holds implications with regard to the species that is directly engaged in the catalytic oxidation of alkenes. Through a combination of UV/Vis absorption, Raman, resonance Raman and electron paramagnetic resonance (EPR) spectroscopy, it is shown that the conversion proceeds by an autocatalytic mechanism and that the species that engages in the oxidation of organic substrates also catalyses H2O2 decomposition, and the former process is faster. The in situ formation of catalytically active species through the reduction of a precatalyst, H2O2 disproportionation and alkene oxidation are linked to a common active species.
Bioinspired nonheme iron complexes derived from an extended series of N,N,O-ligated BAIP ligands
Moelands, Marcel A. H.,Nijsse, Sjoerd,Folkertsma, Emma,De Bruin, Bas,Lutz, Martin,Spek, Anthony L.,Klein Gebbink, Robertus J. M.
, p. 7394 - 7410 (2013)
A series of mononuclear Fe(II) triflate complexes based on the 3,3-bis(1-alkylimidazole-2-yl)propionate ester (BAIP) ligand scaffold are reported. In these complexes, the tripodal N,N,O-BAIP ester ligand is varied by (i) changing the ester moiety (i.e., n-Pr, tert-Bu esters, n-Pr amide), (ii) changing the methylimidazole moieties to methylbenzimidazole moieties, and (iii) changing the methylimidazole moieties to 1-ethyl-4-isopropylimidazole moieties. The general structure of the resulting complexes comprises two facially capping BAIP ligands around a coordinatively saturated octahedral Fe(II) center, with either a transoid or cisoid orientation of the N,N,O-donor manifold that depends on the combined steric and electronic demand of the ligands. In the case of the sterically most encumbered ligand, a four-coordinate all N-coordinate complex is formed as well, which cocrystallizes with the six-coordinate complex. In combination with the catalytic properties of the new complexes in the epoxidation/cis-dihydroxylation of cyclooctene with H2O2, in terms of turnover number and cis-diol formation, these studies provide a number of insights for further ligand design and catalyst development aimed at Fe-mediated cis-dihydroxylation.
cis-Dihydroxylation of olefins by a non-heme iron catalyst: A functional model for Rieske dioxygenases
Chen, Kui,Lawrence Jr., Que
, p. 2227 - 2229 (1999)
The first iron complex capable of olefin cis-dihydroxylation in combination with H2O2 provides a functional model for Rieske dioxygenases. Mechanistic studies on the model reaction suggest the participation of an Fe(III)(η2-OOH) intermediate, with the oxygen atoms coming exclusively from H2O2 (see reaction scheme; L denotes a tris(6-methyl-2-pyridylmethyl)amine ligand, Solv = solvent). The similarities between the model and the enzymes strengthen the proposal that an Fe(III)- peroxo intermediate is involved in the enzymatic reactions.
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Cope et al.
, (1957)
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Bioinspired symmetrical and unsymmetrical diiron complexes for selective oxidation catalysis with hydrogen peroxide
Trehoux, Alexandre,Guillot, Régis,Clemancey, Martin,Blondin, Geneviève,Latour, Jean-Marc,Mahy, Jean-Pierre,Avenier, Frédéric
supporting information, p. 16657 - 16661 (2020/12/18)
Two new symmetrical and unsymmetrical diiron(iii) complexes were synthesized and characterized by X-ray diffraction analysis, mass spectrometry, UV-visible and M?ssbauer spectroscopies. They proved to be good catalysts for alkene and alkane oxidation reactions by H2O2 in acetonitrile solution, and interesting effects of both the nature and the symmetry of the complexes were observed on catalysis in the presence of water.
Cis -Oxoruthenium complexes supported by chiral tetradentate amine (N4) ligands for hydrocarbon oxidations
Tse, Chun-Wai,Liu, Yungen,Wai-Shan Chow, Toby,Ma, Chaoqun,Yip, Wing-Ping,Chang, Xiao-Yong,Low, Kam-Hung,Huang, Jie-Sheng,Che, Chi-Ming
, p. 2803 - 2816 (2018/03/21)
We report the first examples of ruthenium complexes cis-[(N4)RuIIICl2]+ and cis-[(N4)RuII(OH2)2]2+ supported by chiral tetradentate amine ligands (N4), together with a high-valent cis-dioxo complex cis-[(N4)RuVI(O)2]2+ supported by the chiral N4 ligand mcp (mcp = N,N′-dimethyl-N,N′-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine). The X-ray crystal structures of cis-[(mcp)RuIIICl2](ClO4) (1a), cis-[(Me2mcp)RuIIICl2]ClO4 (2a) and cis-[(pdp)RuIIICl2](ClO4) (3a) (Me2mcp = N,N′-dimethyl-N,N′-bis((6-methylpyridin-2-yl)methyl)cyclohexane-1,2-diamine, pdp = 1,1′-bis(pyridin-2-ylmethyl)-2,2′-bipyrrolidine)) show that the ligands coordinate to the ruthenium centre in a cis-α configuration. In aqueous solutions, proton-coupled electron-transfer redox couples were observed for cis-[(mcp)RuIII(O2CCF3)2]ClO4 (1b) and cis-[(pdp)RuIII(O3SCF3)2]CF3SO3 (3c′). Electrochemical analyses showed that the chemically/electrochemically generated cis-[(mcp)RuVI(O)2]2+ and cis-[(pdp)RuVI(O)2]2+ complexes are strong oxidants with E° = 1.11-1.13 V vs. SCE (at pH 1) and strong H-atom abstractors with DO-H = 90.1-90.8 kcal mol-1. The reaction of 1b or its (R,R)-mcp counterpart with excess (NH4)2[CeIV(NO3)6] (CAN) in aqueous medium afforded cis-[(mcp)RuVI(O)2](ClO4)2 (1e) or cis-[((R,R)-mcp)RuVI(O)2](ClO4)2 (1e?), respectively, a strong oxidant with E(RuVI/V) = 0.78 V (vs. Ag/AgNO3) in acetonitrile solution. Complex 1e oxidized various hydrocarbons, including cyclohexane, in acetonitrile at room temperature, affording alcohols and/or ketones in up to 66% yield. Stoichiometric oxidations of alkenes by 1e or 1e? in tBuOH/H2O (5:1 v/v) afforded diols and aldehydes in combined yields of up to 98%, with moderate enantioselectivity obtained for the reaction using 1e?. The cis-[(pdp)RuII(OH2)2]2+ (3c)-catalysed oxidation of saturated C-H bonds, including those of ethane and propane, with CAN as terminal oxidant was also demonstrated.
Photochirogenic nanosponges: phase-controlled enantiodifferentiating photoisomerization of (Z)-cyclooctene sensitized by pyromellitate-crosslinked linear maltodextrin
Liang, Wenting,Zhao, Meiling,Wei, Xueqin,Yan, Zhiqiang,Wu, Wanhua,Caldera, Fabrizio,Trotta, Francesco,Inoue, Yoshihisa,Su, Dan,Zhong, Zhihui,Yang, Cheng
, p. 17184 - 17192 (2017/03/30)
Linear maltodextrin (LM) was cross-linked by pyromellitic dianhydride to afford LM polymers of different cross-linking degrees. When soaked in water, these cross-linked LM polymers (nanosponges (NSs)), evolved into several phases from sol to suspension, then to flowing gel, and finally to rigid gel with an increase in their content. Enantiodifferentiating photoisomerization of (Z)-cyclooctene (1Z) to chiral (E)-isomer (1E), which was employed as a benchmark reaction to quantitatively assess the environmental-to-molecular chirality transfer process, was performed in aqueous media containing these pyromellitate-crosslinked LM-NSs in different phases. The enantiomeric excess (ee) of 1E obtained was relatively insensitive to the phases at least up to the flowing gel phase, but became highly sensitive in the rigid gel phase, exhibiting an abrupt drop in the early rigid gel phase followed by a rapid recovery in the late rigid gel phase. A comparison with the phase-dependent ee profiles previously reported for similar pyromellitate-crosslinked cyclodextrin (CD)- and cyclic nigerosylnigerose (CNN)-NSs revealed that the chiral void space created around the pyromellitate linker in NS is responsible for the dramatic changes in ee in the rigid gel phase, whereas the inherent host cavity in CD/CNN plays only limited roles in the supramolecular photochirogenesis mediated by the sensitizer-crosslinked NSs. The latter insight allows us to further expand the applicable range of the present concept and methodology by employing a much wider variety of oligosaccharides as well as substrates and sensitizing cross-linkers.
