104196-23-8Relevant articles and documents
Unmatched efficiency and selectivity in the epoxidation of olefins with oxo-diperoxomolybdenum(VI) complexes as catalysts and hydrogen peroxide as terminal oxidant
Maiti, Swarup K.,Dinda, Subhajit,Bhattacharyya, Ramgopal
, p. 6205 - 6208 (2008)
A great variety of olefinic substrates having aromatic, carbocyclic and aliphatic olefins are effectively and selectively oxidized with oxygen-rich molybdenum(VI) complexes, namely [MoO(O2)2·2QOH] 1, [MoO(O2)(QO)2] 2, [Mo(O)2(QO)2] 3, [PPh4][MoO(O2)2(QO)] 4, [PPh4][Mo(O)2(O2)(QO)] 5 and [PPh4][Mo(O)3(QO)] 6 (QOH = 8-quinolinol) as catalyst, NaHCO3 as co-catalyst and H2O2 as the terminal oxidant, at room temperature. Catalysts 1 and 4 show unmatched yield, turnover number (TON) and turnover frequency (TOF), and hence shortest reaction time.
The dihydrofuran template approach to furofuran synthesis
Aldous, David J.,Batsanov, Andrei S.,Yufit, Dmitrii S.,Dalenon, Anne J.,Dutton, William M.,Steel, Patrick G.
, p. 2912 - 2927 (2006)
Flash vacuum pyrrolysis of vinyl epoxides provides cis-dihydrofuran carboxylic esters in good yields and diastereoselectivities, which, on base-promoted epimerisation afford the complementary trans series. The compounds provide a viable template for a Lewis acid promoted cyclisation to provide the 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane core found in the furofuran series of natural lignans. This strategy is stereodivergent and can be controlled to provide the exo-exo, exo-endo or endo-endo stereochemistries. The approach has been exemplified in syntheses of the sesamyl furofurans (±)-epiasarinin and (±)-asarinin. The Royal Society of Chemistry 2006.
Highly enantioselective and efficient asymmetric epoxidation catalysts: Inorganic nanosheets modified with α-amino acids as ligands
Wang, Jiuzhao,Zhao, Liwei,Shi, Huimin,He, Jing
, p. 9171 - 9176 (2011)
Layered catalyst: The attachment of α-amino acid ligands to inorganic nanosheets for use as ligands to vanadium, resulted in a catalyst that enhanced the enantioselectivity of the epoxidation of allylic alcohols (see picture). The catalyst can be colloidized, allowing for the catalytic reactions to be carried out under pseudo-homogeneous reaction conditions and also the catalysts to be directly recycled by simple liquid/liquid separation. Copyright
Co(thd)2: A superior catalyst for aerobic epoxidation and hydroperoxysilylation of unactivated alkenes: Application to the synthesis of spiro-1,2,4-trioxanes
O'Neill, Paul M.,Hindley, Stephen,Pugh, Matthew D.,Davies, Jill,Bray, Patrick G.,Park, B. Kevin,Kapu, Dauda S.,Ward, Stephen A.,Stocks, Paul A.
, p. 8135 - 8138 (2003)
Bis(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt(II) (Co(thd) 2), a β-diketonate prepared in a simple one-step procedure, is an excellent catalyst for aerobic epoxidation and Mukaiyama-Isayama hydroperoxysilylation of unactivated alkenes. For hydroperoxysilylation, Co(thd)2 is superior to Co(acac)2 and can catalyse oxidation of cyclic alkenes in excellent yield. Chiral β-diketonate or keto iminato catalysts failed to catalyse this reaction in an enantioselective manner and a free radical mechanism consistent with this observation is proposed. Hydroperoxysilylation of cyclohex-1-enylmethanol by Co(thd) 2 followed by addition of a ketone/TsOH provides a simple one-pot procedure for the synthesis of spiro-1,2,4-trioxane antimalarials.
Enantio- and stereo-selective route to the taxol side chain via asymmetric epoxidation of trans-cinnamyl alcohol and subsequent epoxide ring opening
Bonini,Righi
, p. 2767 - 2768 (1994)
The first route to the side chain of Taxol and Taxotere, employing asymmetric epoxidation (AE) of trans-cinnamyl alcohol and a new highly regio- and stereo-selective opening of the epoxide ring with MgBr2, is described.
2,2,2-Trifluoroacetophenone: An organocatalyst for an environmentally friendly epoxidation of alkenes
Limnios, Dimitris,Kokotos, Christoforos G.
, p. 4270 - 4276 (2014)
A cheap, mild, fast, and environmentally friendly oxidation of olefins to the corresponding epoxides is reported using polyfluoroalkyl ketones as efficient organocatalysts. Namely, 2,2,2-trifluoroacetophenone was identified as an improved organocatalyst for the epoxidation of alkenes. Various olefins, mono-, di-, and trisubstituted, are epoxidized chemoselectively in high to quantitative yields utilizing 2-5 mol % catalyst loading and H2O 2 as the green oxidant.
Efficient biocatalysis for the production of enantiopure (S)-epoxides using a styrene monooxygenase (SMO) and Leifsonia alcohol dehydrogenase (LSADH) system
Toda, Hiroshi,Imae, Ryouta,Itoh, Nobuya
, p. 1542 - 1549 (2012)
Herein we report the production of enantiopure epoxides through biocatalysis using recombinant Escherichia coli cells expressing Rhodococcus sp. ST-10 styrene monooxygenase (SMO) and Leifsonia sp. S749 alcohol dehydrogenase (LSADH) genes are described. Rhodococcus sp. ST-10 SMO catalyzed the epoxidation of various alkenes, including styrene derivatives, vinyl pyridines, and linear alkenes, to give (S)-epoxides. NADH was regenerated by the reduction of NAD + by LSADH with 2-propanol. The E. coli biocatalyst was used in an aqueous/organic biphasic reaction system and the reaction conditions were optimized. Under the optimized conditions, 170 mM of (S)-styrene oxide was obtained from styrene in the organic phase with excellent enantiomeric excess (99.8%). This biocatalytic process was used to synthesize various (S)-epoxides.
Catalytic oxaziridinium-mediated epoxidation of olefins by Oxone. A convenient catalyst excluding common side reactions
Bohé, Luis,Kammoun, Majed
, p. 803 - 805 (2002)
The nicely crystalline, easily prepared and handled, 3,3-dimethyl-3,4-dihydroisoquinolinium salt 6, is a convenient catalyst for the oxaziridinium-mediated epoxidation of alkenes by Oxone.
Cyclohexanones derived from dihydrocarvone as precursor of chiral dioxiranes for epoxidation of olefins
Solladié-Cavallo, Arlette,Jierry, Lo?c,Lupattelli, Paolo,Bovicelli, Paolo,Antonioletti, Roberto
, p. 11375 - 11381 (2004)
New ketones having an axial α-fluorine atom and substituents other than fluorine at C8, derived from commercially available (+)-dihydrocarvone, have been prepared and used for epoxidations of trans stilbene, trans methyl p-methoxy cinnamate, trans cinnamyl alcohol and derivatives. It was found that replacement of the H at C8 by a substituent containing an oxygen atom increases the enantioselectivities in all cases. It was also shown that protic substituents (hydroxyl groups) provide a decrease in enantioselectivity in the case of cinnamates probably because of H-bonding dioxirane-substrate. It is noted that the absolute configurations of the various epoxides obtained hold with the usual model involving a spiro-approach on the dioxirane conformation C1 having the α-fluorine axial. Moreover, sub-stoichiometric amounts (0.3 equiv) of ketone can be used in all cases as these ketones do not undergo Baeyer-Villiger oxidation and are recovered. Graphical abstract.
The diastereoselective epoxidation of olefins in supercritical carbon dioxide
Haas, Geoffrey R.,Kolis, Joseph W.
, p. 5923 - 5926 (1998)
Allylic alcohols are epoxidized with tert-butyl hydroperoxide in the presence of a vanadyl salen oxo-transfer catalyst in supercritical CO2. The metal catalyst was prepared in a simple two step, Schiff base reaction to form the salen ligand, followed by complexation to the vanadyl group. The epoxidation reactions are clean and give both high yields and good diastereoselectivity.
Efficient and selective oxidation of alcohols to carbonyl compounds at room temperature by a ruthenium complex catalyst and hydrogen peroxide
Wang, Jie-Xiang,Zhou, Xian-Tai,Han, Qi,Guo, Xiao-Xuan,Liu, Xiao-Hui,Xue, Can,Ji, Hong-Bing
, p. 19415 - 19421 (2019)
In this study, convenient and selective oxidation of alcohols using aqueous hydrogen peroxide to yield carbonyl compounds was studied. Using the ruthenium-(4-methylphenyl-2,6-bispydinyl) pyridinedicarboxylate complex [Ru(mpbp)(pydic)] as a catalyst, primary and secondary alcohols were oxidized to aldehydes and ketones at room temperature with a satisfactory yield and excellent selectivity. The influence of various reaction parameters, such as solvent, catalyst and oxidant amount on both the activity and selectivity was also evaluated. Kinetic studies showed that the oxidation of alcohol was first order in terms of the substrate and hydrogen peroxide, and was second order in terms of the catalyst. A plausible mechanism involving ruthenium-oxo species with electrophilic character was proposed based on the in situ UV-vis spectroscopy studies and Hammett plots.
Synthesis and catalytic epoxidation potential of oxodiperoxo molybdenum(VI) complexes with 2-hydroxybenzohydroxamate and 2-hydroxybenzoate: The crystal structure of PPh4[MoO(O2)2(HBA)]
Gharah, Narottam,Chattopadhyay, Basab,Maiti, Swarup K.,Mukherjee, Monika
, p. 531 - 539 (2010)
(PPh4)2[MoO(O2)2(SHAH)] ·H2O and PPh4[MoO-(O2)2(HBA)] (SHAH3 = 2-hydroxybenzohydroxamic acid and HBAH = 2-hydroxybenzoic acid) have been synthesized and characterized by physico-chemical and spectroscopic methods. In addition, the second complex has been structurally characterized by single-crystal X-ray diffraction analysis. We have compared the catalytic activities of these two new complexes, together with the previously reported PPh4[MoO(O2)2(BZ)] (BZH = benzoic acid), with respect to the epoxidation of alkenes. The hydroxamate complex is the most efficient catalyst among the three complexes, showing excellent catalytic activity for the substrates cyclohexene, cyclooctene, cinnamyl alcohol, pent-4-en-1-ol and hex-1-ene. Springer Science+Business Media B.V. 2010.
Oxazolidine sulfur ylides derived from phenylglycinol for the specific and highly diastereoselective synthesis of aryl and alkyl trans-epoxyamides
Gordillo, Paola G.,Aparicio, David M.,Flores, Marcos,Mendoza, Angel,Orea, Laura,Juarez, Jorge R.,Huelgas, Gabriela,Gnecco, Dino,Teran, Joel L.
, p. 5561 - 5565 (2013)
Aryl and alkyl chiral oxazolidine sulfonium salts with cis and trans dispositions derived from (-)-(R)-2-phenylglycinol were demonstrated to be good to excellent chiral auxiliaries for the diastereoselective synthesis of (2R,3S)-trans-epoxyamides. Interes
Selective photocatalytic oxidation of alcohols to corresponding aldehydes in solvent-free conditions using porphyrin sensitizers
Mehrabi-Kalajahi, Seyed Saeed,Hajimohammadi, Mahdi,Safari, Nasser
, p. 1069 - 1076 (2016)
Abstract: In this work, selective and aerobic photooxidation of a range of aromatic, aliphatic and α,β-unsaturated alcohols to corresponding carbonyl compounds has been performed with tetraphenylporphyrin (H2TPP), ClFeTPP and ZnTPP as sensitizers using visible light and in the presence of molecular oxygen in solvent-free conditions. The conversion rates for alcohols oxidations were in the order of free-base porphyrin (H2TPP)?>?metalloporphyrin (ClFeTPP) and (ZnTPP). This method has a wide range of applications, remarkable conversion and product yield in reasonable time, does not include cumbersome work-up, exhibits chemoselectivity, and proceeds under mild reaction conditions. As the matter of oxidation of cycloheptanol and cyclooctanol using H2TPP as photosensitizer, the TON reached up to 1686 and 2464, respectively and selectivity more than 99?%. Graphical abstract: [Figure not available: see fulltext.]
New chiral amino alcohol ligands for catalytic enantioselective addition of diethylzincs to aldehydes
Sappino, Carla,Mari, Alessandra,Mantineo, Agnese,Moliterno, Mauro,Palagri, Matteo,Tatangelo, Chiara,Suber, Lorenza,Bovicelli, Paolo,Ricelli, Alessandra,Righi, Giuliana
, p. 1860 - 1870 (2018)
A study aimed at the synthesis and structure optimization of new, efficient, optically active β-amino alcohol ligands with a structure suitable for immobilization on magnetite nanoparticles has been carried out. The optimized homogeneous amino alcohol catalysts 13a and 13b, the chirality of which arises from the Sharpless epoxidation of suitable allyl alcohols, were tested by employing the well-established enantioselective amino alcohol-promoted addition of diethylzinc to benzaldehyde, giving the corresponding benzyl alcohol with nearly quantitative yield and ee = 95%. Then, their broad applicability as chiral catalysts was evaluated by carrying out the same reaction on a family of aldehydes, including variously substituted aromatic ones as well as an aliphatic analogue. The results have confirmed the validity of the fine-tuning process performed on ligands 13a and 13b. In fact, both exhibited excellent catalytic activity as demonstrated by the chemical yields and ee obtained from all the tested aldehydes, almost independent of the position and type of substitution in the aromatic ring.
Liquid-Phase Synthesis of Chiral Tartrate Ligand Library for Enantioselective Sharpless Epoxidation of Allylic Alcohols
Guo, Hong-Chao,Shi, Xue-Yan,Wang, Xian,Liu, Shang-Zhong,Wang, Min
, p. 2042 - 2047 (2004)
This paper reports a successful development of a group of efficient soluble polymer-supported chiral tartrate ligands by liquid-phase synthesis for Sharpless epoxidation of a variety of allylic alcohols through ligand diversity. The influence of substituent in chiral tartrate ligands on the enantioselectivities of the reaction was disclosed. Moderate chemical yields and good enantiomeric excesses were obtained by using soluble polymer-supported tartrate ester in the epoxidation of allylic alcohols with Ti(O-i-Pr) 4/tert-butyl hydroperoxide.
Niobium peroxide-catalyzed selective epoxidation of allylic alcohols
Chen, Chen,Zhao, Xiuge,Chen, Jizhong,Hua, Li,Zhang, Ran,Guo, Li,Song, Baoning,Gan, Huimei,Hou, Zhenshan
, p. 3231 - 3238 (2014)
Modified niobium peroxides were prepared and used for catalyzing the epoxidation of allylic alcohols with hydrogen peroxide in the absence of any other solvent under ice bath conditions. Niobium peroxides modified with ionic liquid-type 1-dodecyl- 3-methylimidazolium hydroxide or conventional tetradecyl trimethyl ammonium hydroxide surfactants demonstrated excellent yields (80-99%) for the epoxidation of allylic alcohols to their epoxides even if the reaction was performed without any other solvent at 0°C for 0.5 h. The catalyst characterization demonstrated that the surfactant molecules were anchored on the surface of the niobium catalyst by weak noncovalent interactions. Compared with niobium peroxides, the modified amphiphilic catalysts allowed easier accessibility to hydrophobic substrates and thus demonstrated high reaction rate and excellent recyclability for the epoxidation under mild conditions.
A chemoenzymic approach to the epoxidation of alkenes in aqueous media
Tong, Kit-Ho,Wong, Kwok-Yin,Chan, Tak Hang
, p. 6009 - 6014 (2005)
Hydrogen peroxide, generated insitu by the enzymic oxidation of glucose using glucose oxidase, is coupled to a catalytic system of sodium bicarbonate/manganese sulfate to epoxidize alkenes in aqueous media.
Intermolecular Amine Transfer to Enantioenriched trans-3Phenylglycidates by an α/β-Aminomutase to Access Both anti-Phenylserine Isomers
Shee, Prakash K.,Yan, Honggao,Walker, Kevin D.
, p. 15071 - 15082 (2020)
β-Hydroxy-α-amino acids are noncanonical amino acids with two stereocenters and with useful applications in the pharmaceutical and agrochemical sectors. Here, a 5-methylidene-3,5-dihydro-4H-imidazol-4-one-dependent aminomutase from Taxus canadensis (TcPAM) was repurposed to transfer the amino group irreversibly from (2S)-styryl-α-alanine to exogenously supplied trans-3-phenylglycidate enantiomers, producing anti-phenylserines stereoselectively. TcPAM catalysis inverted the intrinsic regioselective chemistry from amination at Cβ to Cα of enantioenriched trans-3-phenylglycidates to make phenylserine predominantly (97%)phenylisoserine (～3% relative abundance). Gas chromatography?mass spectrometry analysis of the chiral auxiliary derivatives of the biocatalyzed products confirmed that the amine transfer was stereoselective for each glycidate enantiomer. TcPAM converted (2S,3R)-3-phenylglycidate to (2S)-anti-phenylserine predominantly (89%) and (2R,3S)-3-phenylglycidate to (2R)-anti-phenylserine (88%)their antipodes, with inversion of the configuration at Cα in each case. Both glycidate enantiomers formed a small amount (～10%) of syn-phenylserine by retaining the configuration at Cα. The minor syn-isomer likely came from a β-hydroxy oxiranone intermediate formed by intramolecular ring opening of the oxirane ring by the carboxylate before amine transfer. TcPAM had a slight preference toward (2S,3R)-3-phenylglycidate, which was turned(kcat = 0.3 min?1) 1.5 times faster than the (2R,3S)-glycidate (kcat = 0.2 min?1). The catalytic efficiencies (kcatapp/KMapp ≈ 20 M?1s?1) of TcPAM for the antipodes were similar. The kinetic data supported a two-substrate ping-pong mechanism for the amination of the phenylglycidates, with competitive inhibition at higher glycidate substrate concentrations.
Borylation and rearrangement of alkynyloxiranes: A stereospecific route to substituted α-enynes
Fuentespina, Ruben Pomar,De La Cruz, José Angel Garcia,Durin, Gabriel,Mamane, Victor,Weibel, Jean-Marc,Pale, Patrick
, p. 1416 - 1424 (2019)
1,3-Enynes are important building blocks in organic synthesis and also constitute the key motif in various bioactive natural products and functional materials. However, synthetic approaches to stereodefined substituted 1,3-enynes remain a challenge, as they are limited to Wittig and cross-coupling reactions. Herein, stereodefined 1,3-enynes, including tetrasubstituted ones, were straightforwardly synthesized from cis or trans-alkynylated oxiranes in good to excellent yields by a one-pot cascade process. The procedure relies on oxirane deprotonation, borylation and a stereospecific rearrangement of the so-formed alkynyloxiranyl borates. This stereospecific process overall transfers the cis or trans-stereochemistry of the starting alkynyloxiranes to the resulting 1,3-enynes.
Practical and environmentally friendly epoxidation of olefins using Oxone
Hashimoto, Norio,Kanda, Atsushi
, p. 405 - 406 (2002)
A practical and efficient epoxidation of aromatic olefins using Oxone in a two-phase system (ethyl acetate - water) is described. The reported method is suitable for large-scale synthesis and does not require phase transfer catalyst (PTC) or pH control.
A simple, iron-catalyzed, pyridine-assisted hydrogen peroxide epoxidation system
Jiao, Mingyu,Matsunaga, Hirofumi,Ishizuka, Tadao
, p. 799 - 801 (2011)
A simple and inexpensive system comprised of H2O 2-pyridine-FeCl3 · 6H2O for the catalysis of olefin epoxidation was established. Intriguingly, the reactivity of this system greatly depends on the amounts of pyridine. Various substrates, including aromatic and aliphatic olefins, were epoxidized by this simple system in moderate to excellent yields.
An Improved Asymmetric Epoxidation of Allyl Alcohols using Titanium-pillared Montmorillonite as a Heterogeneous Catalyst
Choudary, B. M.,Valli, V. L. K.,Prasad, A. Durga
, p. 1186 - 1187 (1990)
A simple and convenient procedure for the catalytic asymmetric epoxidation of primary allyl alcohols with high enantiomeric purities and good yields using a heterogeneous titanium-pillared montmorillonite catalyst is demonstrated.
Chiral vanadium-based catalysts for asymmetric epoxidation of allylic alcohols
Murase, Noriaki,Hoshino, Yujiro,Oishi, Masataka,Yamamoto, Hisashi
, p. 338 - 339 (1999)
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Highly facile homogeneous epoxidation of olefins using oxo-diperoxo tungstate(VI) complex as catalyst, bicarbonate as co-catalyst and hydrogen peroxide as a terminal oxidant
Maiti, Swarup K.,Dinda, Subhajit,Gharah, Narottam,Bhattacharyya, Ramgopal
, p. 479 - 489 (2006)
Addition of a dilute acetic acid solution of 8-quinolinol to an H 2O2 solution of freshly precipitated H2WO 4·2H2O furnishes a yellow adduct [WO(O 2)2·2QOH] 1 which, on crystallization from a suitable solvent, affords orange-yellow complex [WO(O2)(QO) 2] 2. When 2 reacts stoichiometrically with olefinic compounds in a 1:1 molar ratio, the respective olefins are epoxidized and 2 is converted to the orange-red [WO2(QO)2] 3. When 1 is treated with an excess of H2O2 (greater than 6 equiv.) and PPh4Cl, an anionic light yellow complex PPh4[WO(O2)2(QO)] 4 is obtained. 4 reacts with cyclopentene (a representative olefin) in a 1:1 molar ratio producing cyclopentene oxide and itself is converted to PPh 4[WO2(O2)(QO)] 5. If the above reaction is conducted at a 1:2 molar ratio (instead of 1:1) then 2 moles of the corresponding epoxide is formed and 4 is converted to PPh4[WO 3(QO)] 6. All these peroxo complexes have remarkable catalytic efficiencies in the epoxidation of olefinic compounds when used in tandem with NaHCO3 as co-catalyst and H2O2 as oxidant in a CH3CN medium at room temperature, the method being green and economical. The catalyst 4 under the above experimental conditions shows so far unmatched efficiency in epoxidizing a wide variety of olefinic substrates. the Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2006.
First Total Synthesis of Jomthonic Acid A 1
Dumpala, Mohan,Radha Krishna, Palakodety,Srinivas, Batthula
supporting information, p. 69 - 72 (2019/12/30)
A stereoselective total synthesis of jomthonic acid A is described. The key features of the synthetic strategy are a Sharpless asymmetric epoxidation, a Gilmann reagent-induced methylation, a Mitsunobu reaction, a Yamaguchi esterification, and an O -(benzotriazol-1-yl)- N, N, N ′, N ′-tetramethyluronium tetrafluoroborate (TBTU)-mediated amide coupling. Jomthonic acid A is an architecturally rare amino acid containing a β-methylphenylalanine residue and a 4-methyl-(2 E,4 E)-hexa-2,4-dienoate moiety. It shows antidiabetic and antiatherogenic activities when tested against mouse ST-13 preadiopocytes.
Enantiocomplementary Epoxidation Reactions Catalyzed by an Engineered Cofactor-Independent Non-natural Peroxygenase
Crotti, Michele,Kataja, Kim M.,Poelarends, Gerrit J.,Saravanan, Thangavelu,Xu, Guangcai
supporting information, p. 10374 - 10378 (2020/04/23)
Peroxygenases are heme-dependent enzymes that use peroxide-borne oxygen to catalyze a wide range of oxyfunctionalization reactions. Herein, we report the engineering of an unusual cofactor-independent peroxygenase based on a promiscuous tautomerase that accepts different hydroperoxides (t-BuOOH and H2O2) to accomplish enantiocomplementary epoxidations of various α,β-unsaturated aldehydes (citral and substituted cinnamaldehydes), providing access to both enantiomers of the corresponding α,β-epoxy-aldehydes. High conversions (up to 98 %), high enantioselectivity (up to 98 % ee), and good product yields (50–80 %) were achieved. The reactions likely proceed via a reactive enzyme-bound iminium ion intermediate, allowing tweaking of the enzyme's activity and selectivity by protein engineering. Our results underscore the potential of catalytic promiscuity for the engineering of new cofactor-independent oxidative enzymes.
