111-70-6Relevant articles and documents
THE DIMESITYLBORON GROUP IN ORGANIC SYNTHESIS 2. THE C-ALKYLATION OF ALKYLDIMESITYLBORANES
Pelter, Andrew,Williams, Lorraine,Wilson, John W.
, p. 627 - 630 (1983)
It is demonstrated that anions α to the dimesitylboron group are alkylated at carbon in excellent yields.The alkylations may be repeated, so allowing for one-pot, one, two or three insertion reactions.
Selective aldehyde reduction in ketoaldehydes with NaBH4-Na 2CO3-H2O at room temperatures
Chandrasekhar, Sosale,Shrinidhi, Annadka
, p. 2051 - 2056 (2014)
A variety of aliphatic and aromatic ketoaldehydes were reduced to the corresponding ketoalcohols with a mixture of sodium borohydride (1.2 equivalents) and sodium carbonate (sixfold molar excess) in water. Reactions were performed at room temperatures(typically) 2 h, and yields of isolated products generally ranged from 70% to 85%. A bis-carbonate-borane complex, [(BH3)2CO2]2- 2Na+, possibly formed from the reagent mixture, is likely the active reductant. The moderated reactivity of this acylborane species would explain the chemoselectivity observed in the reactions. The readily available reagents and the mild aqueous conditions make for ease of operation and environmental compatibility, and make a useful addition to available methodology. Copyright
Copper-Catalyzed Borylative Methylation of Alkyl Iodides with CO as the C1 Source: Advantaged by Faster Reaction of CuH over CuBpin
Wu, Fu-Peng,Wu, Xiao-Feng
, p. 11730 - 11734 (2021)
CuH and CuBpin are versatile catalysts and intermediates in organic chemistry. However, studies that involve both CuH and CuBpin in the same reaction is still rarely reported due to their high reactivity. Now, a study on CuH- and CuBpin-catalyzed borylative methylation of alkyl iodides with CO as the C1 source is reported. Various one carbon prolongated alkyl boranes (RCH2Bpin and RCH(Bpin)2) were produced in moderate to good yields from the corresponding alkyl iodides (RI). In this cooperative system, CuH reacts with alkyl iodide faster than CuBpin.
Catalytic Reactions of Metalloporphyrins. 3. Catalytic Modification of Hydroboration-Oxidation of Olefin with Rhodium(III) Porphyrin as Catalyst
Aoyama, Yasuhiro,Tanaka, Yasutaka,Fujisawa, Takeshi,Watanabe, Takamichi,Toi, Hiroo,Ogoshi, Hisanobu
, p. 2555 - 2559 (1987)
(Octaethylporphyrinato)- or (tetraphenylporphyrinato)rhodium(III) chloride catalyzes the anti-Marcovnikov "hydration" of olefin with NaBH4 and O2 in THF. 1,5-Cyclooctadiene gives rise to cyclooctanol and 1,5-cyclooctanediol (in a ratio of approximately 1:2), and acetylenes are converted directly to alcohols under similar conditions.The initial step in the catalytic reaction of olefin is the hydride and borane transfers from BH4- respectively to RhIII porphyrin and olefin to give hydridorhodium (RhH) porphyrin and alkylborane.The RhH species undergoesoxidation with O2 back to RhIII with concomitant oxidation of alkylborane with retention of configuration.This coupled oxidation of alkylborane is in competition with its nonstereospecific autooxidation without assistance of Rh-H.The present system provides a catalytic modification of hydroboration-oxidation of olefin in the presence of oxygen, as illustrated by the one-pot conversion of 1-methylcyclohexene to (E)-2-methylcyclohexanol with 100 percent regioselectivity and up to 97 percent stereoselectivity.
Highly efficient, general hydrogenation of aldehydes catalyzed by PNP iron pincer complexes
Zell, Thomas,Ben-David, Yehoshoa,Milstein, David
, p. 822 - 826 (2015)
A general protocol for the synthetically and industrially important hydrogenation of aldehydes to alcohols is reported. The reactions are catalyzed by well-defined iron pincer complexes that are capable of hydrogenation of aliphatic and aromatic aldehydes selectively and efficiently under mild conditions, with unprecedented turnover numbers.
Heptanuclear Fe5Cu2-Phenylgermsesquioxane containing 2,2′-Bipyridine: Synthesis, Structure, and Catalytic Activity in Oxidation of C-H Compounds
Bilyachenko, Alexey N.,Khrustalev, Victor N.,Zubavichus, Yan V.,Shul'Pina, Lidia S.,Kulakova, Alena N.,Bantreil, Xavier,Lamaty, Frédéric,Levitsky, Mikhail M.,Gutsul, Evgeniy I.,Shubina, Elena S.,Shul'Pin, Georgiy B.
, p. 528 - 534 (2018)
A new representative of an unusual family of metallagermaniumsesquioxanes, namely the heterometallic cagelike phenylgermsesquioxane (PhGeO2)12Cu2Fe5(O)OH(PhGe)2O5(bipy)2 (2), was synthesized and structurally characterized. Fe(III) ions of the complex are coordinated by oxa ligands: (i) cyclic (PhGeO2)12 and acyclic (Ph2Ge2O5) germoxanolates and (ii) O2- and (iii) HO- moieties. In turn, Cu(II) ions are coordinated by both oxa (germoxanolates) and aza ligands (2,2′-bipyridines). This "hetero-type" of ligation gives in sum an attractive pagoda-like molecular architecture of the complex 2. Product 2 showed a high catalytic activity in the oxidation of alkanes to the corresponding alkyl hydroperoxides (in yields up to 30%) and alcohols (in yields up to 100%) and in the oxidative formation of benzamides from alcohols (catalyst loading down to 0.4 mol % in Cu/Fe).
Two new approaches to the 25-hydroxy-vitamin D2 side chain
Wilson,Davey,Guazzaroni
, p. 2007 - 2012 (1992)
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Shape-selective Alkane Hydroxylation
Suslick, Kenneth,Cook, Bruce,Fox, Mary
, p. 580 - 582 (1985)
A series of sterically hindered manganese porphyrins have been used to catalyse shape-selective alkane hydroxylation, increasing the production of primary alcohols.
Efficient deprotection of tetrahydropyranyl ethers by bismuth(III) salts
Mohammadpoor-Baltork, Iraj,Kharamesh, Bahram,Kolagar, Sadegh
, p. 1633 - 1637 (2002)
Treatment of tetrahydropyranyl(THP) ethers with bismuth(III) salts including BiC13, Bi(TFA)3 and Bi(OTf)3 in methanol provides a simple and efficient process for deprotection of these ethers and the parent alcohols were obtained in excellent yields.
Interplay between Substrate and Proton Donor Coordination in Reductions of Carbonyls by SmI2-Water Through Proton-Coupled Electron-Transfer
Chciuk, Tesia V.,Anderson, William R.,Flowers, Robert A.
, p. 15342 - 15352 (2018)
The reduction of a carbonyl by SmI2-water is the first step in a range of reactions of synthetic importance. Although the reduction is often proposed to proceed through an initial stepwise electron-transfer-proton-transfer (ET-PT), recent work has shown that carbonyls and related functional groups are likely reduced though proton-coupled electron-transfer (PCET). In the present work, the reduction of an activated ester, aldehyde, a linear and cyclic ketone, and related sterically demanding carbonyls by SmI2-H2O was examined through a series of mechanistic experiments. Kinetic studies demonstrate that all substrates exhibit significant increases in the rate of reduction by SmI2 as [H2O] is increased. Under identical conditions, ketones and an aldehyde containing a methyl adjacent to the carbonyl are reduced slower than an unsubstituted variant by an order of magnitude, demonstrating the importance of substrate coordination. In the case of unactivated substrates, rates of reduction show excellent correlation with the calculated bond dissociation free energy of the O-H bond of the intermediate ketyl and the calculated free energy of intermediate ketyl radical anions derived from unhindered substrates: findings consistent with concerted PCET. Activated esters derived from methylbenzoate are likely reduced through stepwise or asynchronous PCET. Overall, this work demonstrates that the combination of the coordination of substrate and water to Sm(II) provides a configuration uniquely suited to a coupled electron- and proton-transfer process.
Highly efficient transfer hydrogenation of aldehydes and ketones using potassium formate over AlO(OH)-entrapped ruthenium catalysts
Gao, Yanxiu,Jaenicke, Stephan,Chuah, Gaik-Khuan
, p. 51 - 58 (2014)
Ruthenium encapsulated in an aluminium oxyhydroxide-support was investigated for the transfer hydrogenation of aldehydes and ketones with potassium formate as a sustainable green hydrogen donor. The entrapped ruthenium were narrowly distributed with mean diameters of 1.5-1.8 nm. XPS studies show that the ruthenium was present as Ru0 and Ru3+. The catalysts showed high activity even at low metal loadings of 0.5-2 wt.%. The maximum TOF for benzaldehyde hydrogenation was over 1 wt.% Ru. The reduction of aromatic and aliphatic aldehydes was facile and occurred with 100% yield. In comparison, ketones were less readily reduced although moderate to excellent yields could be obtained after a longer reaction time. No leaching of ruthenium was observed in contrast to a catalyst prepared by wet impregnation. Washing of the used catalyst with water and ethanol effectively removed the deposited bicarbonate co-product and the recycled catalyst maintained its activity up to five runs.
Water-soluble, 1,3,5-Triaza-7-phosphaadamantane-stabilized palladium nanoparticles and their application in biphasic catalytic hydrogenations at room temperature
Caporali, Maria,Guerriero, Antonella,Ienco, Andrea,Caporali, Stefano,Peruzzini, Maurizio,Gonsalvi, Luca
, p. 2517 - 2526 (2013)
Water-dispersible Pd nanoparticles stabilized by the hydrophilic cage-like aminophosphine ligand 1,3,5-triaza-7-phosphaadamantane and its N-methyl derivative were synthesized and fully characterized in the colloidal state by TEM, and NMR and UV spectroscopy and in the solid state by X-ray photoelectron spectroscopy and powder XRD. The three different nanoparticles obtained showed a narrow distribution range with average core sizes of 2.8, 3.2, and 3.5nm. The activity of some of these Pd nanoparticles as catalysts in the biphasic hydrogenation of organic substrates under mild conditions has been tested, and good results and excellent reusability (up to nine catalytic runs) were obtained.
Regioselective C-H hydroxylation of: N -alkanes using Shilov-type Pt catalysis in perfluorinated micro-emulsions
De Vos, Dirk E.,Janssen, Michiel
, p. 1264 - 1272 (2020)
Shilov-chemistry inspired catalysis has remained largely overlooked as a tool for establishing the remote hydroxylation of non-polar compounds, such as long linear alkanes, due to the need for an acidic aqueous solution. To circumvent the solubility issue, the concept of micellar catalysis is introduced, using PtII in perfluorinated micro-emulsions. Notably, the terminal C-H activation of n-heptane is demonstrated under an oxygen atmosphere using perfluorooctanoic acid (PFOA) as a surfactant, along with the intrinsic ability of PtII to convert the highly inert primary C-H bonds. Coordination of PtII to the carboxylate groups of PFOA proved to be particularly important for achieving maximum catalyst activity towards the hydrocarbon substrate solubilized inside the micelle interior. Based on these insights, optimization of the reaction parameters allowed a positional selectivity of 60% for 1-heptanol, among the C7 alcohols, to be achieved, using low catalyst and surfactant loadings under acid-free conditions.
Improved regioselectivity in the hydroformylation reaction catalysed by zeolite-encapsulated rhodium(I) species
Andersen, Jo-Ann M.,Currie, Alan W. S.
, p. 1543 - 1544 (1996)
Although zeolite-encapsulated [Rh(CO)x(PR3)y] (PR3 = PEt3, PEt2Ph, PPrn3 or PPh3) give similar chemoselectivities in the hydrocarbonylation of hex-1-ene relative to their homogeneous analogues, the linear : branched ratio can be increased by as much as 10 times.
Oxidation of hydrocarbons with tetra-n-butylammonium peroxy monosulfate catalyzed by β-tetrabromo-meso-tetrakis(4-methoxyphenyl)-and β-tetrabromo-meso-tetraphenylporphyrinatomanganese(III)
Rayati, Saeed,Zakavi, Saeed,Valinejad, Hossein
, p. 611 - 616 (2014)
β-Tetrabromo-meso-tetrakis(4-methoxyphenyl)porphyrin, H2 T(4-OCH3 P)PBr4, was synthesized and characterized by UV-Vis and 1H NMR spectroscopy. Oxidation of alkanes and olefins with tetra-n-butylammonium peroxymonosulfate (n-Bu4NHSO5) was studied in the presence of MnT(4-OCH3 P)PBr4 (OAc) and MnTPPPBr4 (OAc) (TPP = meso-tetraphenylporphyrin). While significance differences were observed between the catalytic activities of the title complexes in the oxidation of alkanes, the 2 manganese porphyrins showed comparable activities in oxidation of most of the olefins used. However, the latter showed greater catalytic performance in the oxidation of the hydrocarbons. Moreover, the oxidative degradation of the former (60%) was greater than that of the latter (45%) in the oxidation of cyclooctene. TUeBITAK.
Cp2TiCl2-CATALYZED GRIGNARD REACTIONS. 3. REACTIONS WITH ESTERS: EFFICIENT METHODOLOGY FOR THE SYNTHESIS OF SECONDARY ALCOHOLS AND FOR THE REDUCTION OF ESTERS TO PRIMARY ALCOHOLS
Sato, Fumie,Jinbo, Takamasa,Sato, Masao
, p. 2175 - 2178 (1980)
Cp2TiCl2-catalyzed Grignard reactions with esters provide general methodology for preparation of secondary alcohols or for reduction of esters to the corresponding primary alcohols.
Miniaturizing biocatalysis: Enzyme-catalyzed reactions in an aqueous/organic segmented flow capillary microreactor
Karande, Rohan,Schmid, Andreas,Buehler, Katja
, p. 2511 - 2521 (2011)
A segmented flow capillary microreactor was used to perform the enzyme-catalyzed conversion of 1-heptaldehyde to 1-heptanol in a two liquid-liquid phase system. These reactor formats are established for chemical reactions but so far data describing the relevant system parameters for enzymatic catalysis are lacking. This work now addresses the impact of important parameters such as capillary diameter, flow velocity, phase ratio, and enzyme as well as substrate concentration on the performance of the enzymatic reaction under segmented flow conditions. All key parameters governing reaction performance have been correlated in a novel operational window for an easy assessment of the various system constraints. Such systems are characterized by high productivities and easy phase separation facilitating downstream processing. This work underscores the importance of segmented flow systems as a promising tool to perform multiphasic enzymatic catalysis. Abbreviations/ Nomenclature: Da: Damkoehler number; kcat: turnover number (s-1); eo: enzyme concentration (mM); I?: phase ratio; kL: mass transfer coefficient (m s-1); a: interfacial area per volume (m-1); CAe: equilibrium substrate concentration in the aqueous phase (mM); CAL: substrate concentration in the bulk aqueous phase (mM); rA: rate of reaction in the aqueous phase; mA: substrate mass transfer into the aqueous phase; STY: space time yield. Copyright
Carbon–Carbon Bond Formation and Hydrogen Production in the Ketonization of Aldehydes
Orozco, Lina M.,Renz, Michael,Corma, Avelino
, p. 2430 - 2442 (2016)
Aldehydes possess relatively high chemical energy, which is the driving force for disproportionation reactions such as Cannizzaro and Tishchenko reactions. Generally, this energy is wasted if aldehydes are transformed into carboxylic acids with a sacrificial oxidant. Here, we describe a cascade reaction in which the surplus energy of the transformation is liberated as molecular hydrogen for the oxidation of heptanal to heptanoic acid by water, and the carboxylic acid is transformed into potentially industrially relevant symmetrical ketones by ketonic decarboxylation. The cascade reaction is catalyzed by monoclinic zirconium oxide (m-ZrO2). The reaction mechanism has been studied through cross-coupling experiments between different aldehydes and acids, and the final symmetrical ketones are formed by a reaction pathway that involves the previously formed carboxylic acids. Isotopic studies indicate that the carboxylic acid can be formed by a hydride shift from the adsorbed aldehyde on the metal oxide surface in the absence of noble metals.
Direct formation of alcohols by hydrocarbonylation of alkenes under mild conditions using rhodium trialkylphosphine catalysts
MacDougall, Joanna K.,Simpson, Michael C.,Green, Michael J.,Cole-Hamilton, David J.
, p. 1161 - 1172 (1996)
The complex [RhH(PEt3)3] catalysed the hydroformylation of hex-1-ene to heptanal and 2-methylhexanal in toluene, but heptanol and 2-methylhexanol were significant products in tetrahydrofuran especially over long reaction times (16 h). In protic solvents only alcohols were produced even after short reaction times. The reactions are very rapid and also occur readily with alkenes such as hex-2-ene, propene, ethene, styrene and 3,3-dimethylbutene. The highest rates observed are for ethene (54 000 turnovers h-1) and the products in all cases are alcohols. Other phosphines containing primary alkyl groups also produced alcohols, but in contrast reactions in ethanol using rhodium complexes containing PPh3, PPh2Et, PPhEt2 or PPri3 produced significant amounts of aldehydes and/or acetals whilst Me2PCH2CH2PMe2 inhibited the reaction. The NMR studies showed that species present in equilibrium in ethanol solution are [RhH(CO)(PEt3)3], [RhH(CO)2(PEt3)2], [Rh2(CO)4(PEt3)4], [Rh2(CO)2(PEt3)6] and PEt3 but that [RhH(CO)(PEt3)3] predominates under the catalytic conditions. Reactions carried out under D2-CO in EtOH produced 90% BuCHDCH2CD2OH/D and 10% BuCHDCH2CHDOH/D but hydrogenation of heptanal under the same conditions gave a mixture of C6H13CHDOH/D (39%) and C6H13CH2OH/D (61%). These results are interpreted to indicate that the alcohols produced from hex-1-ene are primary reaction products and not produced via intermediate aldehydes. A new mechanism for this direct hydrocarbonylation is proposed in which the key acyl intermediate becomes protonated by the alcoholic solvent because of the high electron density it bears as a result of the presence of the electron-donating trialkylphosphines. Oxidative addition of H2 followed by two H-atom transfers leads directly to the alcohol. High pressure NMR studies showed that [Rh{C(O...HOEt)Et}(CO)2(PEt3)2] is present during catalytic hydrocarbonylation of ethene in ethanol. Two different cycles are proposed to explain the products obtained from the catalytic reaction of heptanal with D2-CO. Again, protonation, this time of the metal, appears to be important.
Direct Formation of Alcohols in Homogeneous Hydroformylation catalysed by Rhodium Complexes
MacDougall, Joanna K.,Cole-Hamilton, David J.
, p. 165 - 167 (1990)
Hydroformylation of hex-1-ene catalysed by or /PR3, R = Me, Et, or Bu, produces a mixture of aldehydes and alcohols in toluene or tetrahydrofuran but exclusively alcohols in ethanol; or produce mainly aldehydes or acetals when ethanol is used as the solvent.
Alkylation of Pentaerythritol and Trimethylolpropane, Two Very Hydrophilic Polyols, by Phase-Transfer Catalysis.
Nouguier, R. M.,Mchich, M.
, p. 3296 - 3298 (1985)
Two very hydrophilic polyols, pentaerythritol and trimethylolpropane , can be etherified in good yields by phase-transfer catalysis with allyl chloride or heptyl bromide as alkylating agents.Ion pairs solubilities, lipophilicities of catalysts, and nature of the reaction products which are key factors in achievement of this PTC reaction are discussed.
Hydrogenation of n-heptanal, catalyzed by cobalt carbonyl phosphine complex
Krylova,Vigranenko,Kocheregin
, p. 796 - 799 (2015)
The use of the cobalt carbonyl phosphine complex Co2(CO)6(PR3)2 (R = C4H9) as catalyst precursor allows synthesis of n-heptanol from n-heptanal to be performed with high selectivity.
Directing Selectivity to Aldehydes, Alcohols, or Esters with Diphobane Ligands in Pd-Catalyzed Alkene Carbonylations
Aitipamula, Srinivasulu,Britovsek, George J. P.,Nobbs, James D.,Tay, Dillon W. P.,Van Meurs, Martin
, p. 1914 - 1925 (2021/06/28)
Phenylene-bridged diphobane ligands with different substituents (CF3, H, OMe, (OMe)2, tBu) have been synthesized and applied as ligands in palladium-catalyzed carbonylation reactions of various alkenes. The performance of these ligands in terms of selectivity in hydroformylation versus alkoxycarbonylation has been studied using 1-hexene, 1-octene, and methyl pentenoates as substrates, and the results have been compared with the ethylene-bridged diphobane ligand (BCOPE). Hydroformylation of 1-octene in the protic solvent 2-ethyl hexanol results in a competition between hydroformylation and alkoxycarbonylation, whereby the phenylene-bridged ligands, in particular, the trifluoromethylphenylene-bridged diphobane L1 with an electron-withdrawing substituent, lead to ester products via alkoxycarbonylation, whereas BCOPE gives predominantly alcohol products (n-nonanol and isomers) via reductive hydroformylation. The preference of BCOPE for reductive hydroformylation is also seen in the hydroformylation of 1-hexene in diglyme as the solvent, producing heptanol as the major product, whereas phenylene-bridged ligands show much lower activities in this case. The phenylene-bridged ligands show excellent performance in the methoxycarbonylation of 1-octene to methyl nonanoate, significantly better than BCOPE, the opposite trend seen in hydroformylation activity with these ligands. Studies on the hydroformylation of functionalized alkenes such as 4-methyl pentenoate with phenylene-bridged ligands versus BCOPE showed that also in this case, BCOPE directs product selectivity toward alcohols, while phenylene-bridge diphobane L2 favors aldehyde formation. In addition to ligand effects, product selectivities are also determined by the nature and the amount of the acid cocatalyst used, which can affect substrate and aldehyde hydrogenation as well as double bond isomerization.
Interworking ligand, hydroformylation catalyst and preparation method of dihydric alcohol
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Paragraph 0081; 0089-0090; 0099-0101, (2021/07/09)
The invention discloses an interworking ligand, a hydroformylation catalyst and a preparation method of dihydric alcohol. The interworking ligand comprises a ligand unit I and a ligand unit II, has the characteristics of a bidentate phosphine ligand, and is high in catalytic activity and good in stability; and when the catalyst is used for preparing dihydric alcohol from olefin, linear alcohol can be obtained through a one-step method, and the content of by-products in a traditional series process is reduced. The method has the advantages of simple and convenient process, low cost and energy consumption, good production safety, high product quality and the like, and is particularly suitable for large-scale industrial production.
