79605-67-7Relevant academic research and scientific papers
Influence of the channel size of isostructural 3d-4f MOFs on the catalytic aerobic oxidation of cycloalkenes
Cancino, Patricio,Santiba?ez, Luis,Stevens, Christian,Fuentealba, Pablo,Audebrand, Nathalie,Aravena, Daniel,Torres, Julia,Martinez, Sebastian,Kremer, Carlos,Spodine, Evgenia
supporting information, p. 11057 - 11064 (2019/07/31)
The present work reports a new group of heterogeneous catalysts with a 3D structure, CuLnIDA, {[Cu3Ln2(IDA)6]·8H2O} (Ln: LaIII, GdIII or YbIII), with an organic linker (H2IDA: iminodiacetic acid). Different sets of O2 pressure and time were used in order to obtain the optimal reaction conditions at 75 °C. The reaction was found to depend on the [aldehyde]/[substrate] ratio. The best results, with a conversion of 73% for CuLaIDA as the catalyst, were obtained for the smallest ratio of 0.2. Finally, the importance of the pore size was analysed by comparing the catalytic activity of the as formed catalyst with that of the thermally activated one. The conversion increased ca. 26-35% for the different catalysts when they were previously activated. In addition, the selectivity increased towards cyclohexenone. The use of molecular oxygen as the oxidizing agent in a system where an auxiliary solvent is not used, as the cyclohexene substrate and products play the role of a solvent, permitted us to generate a more friendly environmental system for the oxidation of cycloalkenes under mild conditions.
Aerobic oxidation of the C-H bond under ambient conditions using highly dispersed Co over highly porous N-doped carbon
Nie, Renfeng,Chen, Jingwen,Chen, Minda,Qi, Zhiyuan,Goh, Tian-Wei,Ma, Tao,Zhou, Lin,Pei, Yuchen,Huang, Wenyu
, p. 1461 - 1466 (2019/03/26)
Highly dispersed Co sites in highly porous N-doped carbon (Co-NC) were synthesized by high-temperature pyrolysis of Zn/Co bimetallic zeolitic imidazolate framework-8 (CoxZn100-x-ZIF). Wide characterization indicated that the pyrolysis atmosphere and temperature play crucial roles in the metal dispersion and pore structure of the resulting materials. A hydrogen treatment at elevated temperatures is found to favour the Zn volatilization and restrict the pore shrinkage of the ZIF precursor, thus yielding efficient catalysts with highly dispersed Co, a high surface area (1090 m2 g-1) and pore volume (0.89 cm3 g-1). When used as a catalyst for aerobic oxidation of ethylbenzene (EB), Co1Zn99-ZIF-800-H2 contributes to 98.9% EB conversion and 93.1% ketone selectivity under mild conditions (60 °C, 1 atm O2), which is 41.3 times more active in comparison to the ZIF-67-derived Co catalyst. Co-NC is stable and could be reused four times without obvious deactivation. This catalyst displays good chemoselectivity to the corresponding ketones when using a broad scope of hydrocarbon compounds.
Eco-friendly stereoselective reduction of α,β-unsaturated carbonyl compounds by Er(OTf)3/NaBH4 in 2-MeTHF
Nardi, Monica,Sindona, Giovanni,Costanzo, Paola,Oliverio, Manuela,Procopio, Antonio
, p. 1132 - 1135 (2015/02/19)
An operationally simple and environmentally benign catalytic procedure has been developed to selectively reduce different α,β-unsaturated ketones. The corresponding allylic alcohols are obtained with high chemo- and diastereoselectivity using Er(OTf)3 and NaBH4 in 2-MeTHF. This protocol reduces the amount of catalyst and NaBH4 needed, compared to classical procedures and the stages of extraction/purification are carried out in aqueous solutions avoiding the use of toxic solvents. Taking into account that Er(OTf)3 can be considered even less toxic than table salt and the 'greenness' of 2-MeTHF as a solvent, the system Er(OTf)3/2-MeTHF can be proposed as a cheap, efficient, and environmentally sustainable reduction system for the synthesis of allylic alcohols.
Bismuth-substituted "sandwich" type polyoxometalate catalyst for activation of peroxide: Umpolung of the peroxo intermediate and change of chemoselectivity
Amanchi, Srinivasa Rao,Khenkin, Alexander M.,Diskin-Posner, Yael,Neumann, Ronny
, p. 3336 - 3341 (2015/06/16)
The epoxidation of alkenes with peroxides by WVI, MoVI, VV, and TiIV compounds is well established, and it is well accepted that the active intermediate peroxo species are electrophilic toward nucleophilic substrates. Polyoxotungstates, for example, those of the "sandwich" structure, [WZn(TM-L)2(ZnW9O34)2]q- in which TM = transition metal and L = H2O, have in the past been found to be excellent epoxidation catalysts. It has now been found that substituting the Lewis basic BiIII into the terminal position of the "sandwich" polyoxometalate structure to yield [Zn2BiIII2(ZnW9O34)2]14- leads to an apparent umpolung of the peroxo species and formation of a nucleophilic peroxo intermediate. There are two lines of evidence that support the formation of a reactive nucleophilic peroxo intermediate: (1) More electrophilic sulfoxides are more reactive than more nucleophilic sulfides, and (2) nonfunctionalized aliphatic alkenes and dienes showed ene type reactivity rather than epoxidation pointing toward "dark" formation of singlet oxygen from the nucleophilic intermediate peroxo species. Allylic alcohols reacted much faster than alkenes but showed chemoselectivity toward C-H bond activation of the alcohol and formation of aldehydes or ketones rather than epoxidation. This explained via alkoxide formation at the BiIII center followed by oxidative β-elimination.
Lanthanide replacement in organic synthesis: Luche-type reduction of α,β-unsaturated ketones in the presence of calcium triflate
Forkel, Nina V.,Henderson, David A.,Fuchter, Matthew J.
supporting information; experimental part, p. 2129 - 2132 (2012/09/08)
Development of a calcium-mediated regioselective 1,2-reduction of challenging α,β-unsaturated ketones, such as 2-cyclopententone, is reported. The corresponding allylic alcohols are obtained in very good regioselectivities using Ca(OTf)2 and NaBH4. Furthermore, we have shown that our method can stereoselectively reduce aziridinyl ketones.
Aerobic oxidation of cycloalkenes catalyzed by iron metal organic framework containing N-hydroxyphthalimide
Dhakshinamoorthy, Amarajothi,Alvaro, Mercedes,Garcia, Hermenegildo
experimental part, p. 259 - 265 (2012/06/01)
Iron metal organic framework [Fe(BTC)] loaded with N-hydroxyphthalimide (NHPI) promotes the aerobic oxidation of (cyclo)alkenes to give variable percentages of allylic oxidation products and the corresponding epoxide, dependidng on the nature of the substrate. In the case of cyclopentene and cyclohexene, aerobic oxidation catalyzed by NHPI/Fe(BTC) renders their corresponding unsaturated cyclic alcohol and ketone with 97% selectivity in 5 h at 6% and 12% conversion, respectively. Under the same experimental conditions, cyclooctene exhibited 95% selectivity toward the formation of cyclooctene oxide with 2% of cyclooctenol/one at 4 h. Cycloheptene as susbstrate exhibits an intermediate behavior, and the aerobic oxidation catalyzed by NHPI/Fe(BTC) leads to the formation of cycloheptenol/cycloheptenone with 77% selectivity, accompanied by 23% of cycloheptene oxide at 4 h. Further experiments with non-symmetric olefins exhibited also a mixture of products including epoxides and allyic products. A mechanism to explain these experimental results has been proposed.
Tetrachlorocyclopentadienone O-Oxide, a Facile Oxygen-Atom-Transfer Reagent: The Disproportionation of Cycloalkyldioxyl Radicals
Dunkin, Ian R.,McCluskey, Adam
, p. 1397 - 1400 (2007/10/03)
Photolysis of tetrachlorodiazocyclopentadiene (1) in oxygen-saturated hydrocarbon solvents results in the transient formation of tetrachlorocyclopentadienone O-oxide (3). This rapidly decomposes, giving rise to products derived from oxidation of the hydrocarbons. Cyclopentane, cyclopentene, cycloheptane, cycloheptene, cycloheptatriene, and indene have been studied. Cycloheptatriene and indene gave only low yields of tractable products, but the others gave the corresponding ketones and secondary alcohols as the major products. Although yields varied considerably, the ketone and alcohol products were always obtained, within experimental error, in a 1 : 1 molar ratio. This observed product ratio supports the disproportionation of cycloalkyldioxyl radicals as a crucial step.
A Novel Oxygen-catalysed trans-cis Thermal Isomerization of trans-Cycloheptene
Inoue, Yoshihisa,Ueoka, Toshihiko,Hakushi, Tadao
, p. 2053 - 2056 (2007/10/02)
Contrary to the efficient unimolecular decay to the cis-isomer under an atmosphere of nitrogen, trans-cycloheptene, prepared photochemically in situ at low temperature, underwent second-order trans-cis thermal isomerization under an atmosphere of air without giving any oxidation products.The rate constants and activation parameters are reported for this unique isomerization reaction.Following discussion of the role of oxygen in the isomerization process we propose a mechanism involving termolecular interaction between triplet oxygen and two molecules of the strained cycloalkene.
OAc AS A HOMOGENEOUS CATALYST FOR SELECTIVE ENONE FORMATION BY ALLYLIC OXIDATION OF OLEFINS
Uemura, Sakae,Patil, Suresh R.
, p. 4353 - 4356 (2007/10/02)
Treatment of several cyclic olefins and allylbenzene with a catalytic amount of OAc in acetic acid in the presence of t-butyl hydroperoxide affords the corresponding α,β-unsaturated carbonyl compounds(enones) highly selectively via an ionic pathway.
Direct Epoxy Alcohol Synthesis from Cyclic Olefins Using O2 and VO(acac)2-AIBN Catalyst System
Kaneda, Kiyotomi,Jitsukawa, Koichiro,Itoh, Takashi,Teranishi, Shiichiro
, p. 3004 - 3009 (2007/10/02)
The vanadium-catalyzed oxidation of cyclic olefins with molecular oxygen is examined.The VO(acac)2-AIBN system is an efficient catalyst for epoxy alcohol synthesis.Chloro hydrocarbons such as 1,2-dichloroethane and 1,1,2-trichloroethane are suitable solvents for the epoxidation reaction.Cyclohexene (1), methylcyclohexene (2), and cyclododecene (5) give the corresponding epoxy alcohols in good yields; in the case of 2 with VO(acac)2-AIBN system, the selectivity to epoxy alcohol reaches over 70percent. 1,4-Cyclooctadiene (7) is oxidized to give 9-oxabicyclonon-3-en-exo-2-ol (6a) via the rearrangement of cis-2,3-epoxycyclooct-4-en-1-ol.Exceptional is cyclooctene (4), which gives exclusively cyclooctene oxide (4b).
