- N-heterocyclic carbene piano-stool iron complexes as efficient catalysts for hydrosilylation of carbonyl derivatives
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Hydrosilylation with well defined piano-stool iron(II) complexes bearing both N-heterocyclic carbene and cyclopentadienyl ligands was accomplished with both aldehydes and ketones. Typically, the reduction of aldehydes exhibited good activities (full reduction at 30a°C in 3ah), whereas for ketones, the reaction need 16ah at 70a°C to obtain good conversions. Of notable interest is the use of visible light irradiation to generate one of the active catalyst.
- Jiang, Fan,Bezier, David,Sortais, Jean-Baptiste,Darcel, Christophe
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- Harnessing open-source technology for low-cost automation in synthesis: Flow chemical deprotection of silyl ethers using a homemade autosampling system
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An inexpensive homemade 3-axis autosampler was used to facilitate the automation of an acid catalysed flow chemical desilylation reaction. Harnessing open-source software technologies (Python, OpenCV), an automated computer-vision controlled liquid-liquid extraction step was used to provide effective inline purification. A Raspberry Pi single-board computer was employed to interface with the motors used in the autosampler and actuated fluidic valves.
- O'Brien, Matthew,Konings, Lisette,Martin, Matthew,Heap, Jordan
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- Titanium-mediated formation of 1,2-disubstituted cyclopropanols from esters and alkenes. A new approach to the synthesis of 3,11- dimethylnonacosan-2-one, a sex pheromone of the german cockroach
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A convenient new approach to the synthesis of 3,11-dimethylnonacosan-2- one (1), a component of the sex pheromone of the German cockroach Blattella germanica, using base-induced ring opening of corresponding easily available 1,2-disubstituted cyclopropanols has been performed.
- Epstein, Oleg L.,Kulinkovich, Oleg G.
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- Photochemical deprotection of nitro-substituted benzenesulfenates via photoinduced electron transfer
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The photochemical deprotection of alkyl 2,4-dinitrobenzenesulfenate or alkyl 2-nitrobenzenesulfenate was successfully achieved by addition of triethylamine, while it was unsuccessful without triethylamine. The sulfur-oxygen bond cleavage is thought to occ
- Wakamatsu, Kan,Kouda, Mitsuru,Shimaoka, Kazuyoshi,Yamada, Haruo
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- Selective conversion of enol ethers into alcohols in the presence of alkenes using Hg(OAc)2-NaBH4
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Alkyl enol ethers derived from aldehydes undergo selective oxymercuration-demercuration with aqueous Hg(OAc)2-NaBH4 in the presence of an alkene in good to excellent yield. This method allows the survival of mono-, trans and cis di-, and tri-substituted alkenes as well as cyclic alkenes.
- Crouch, R. David,Mehlmann, John F.,Herb, Brian R.,Mitten, Jeffrey V.,Dai, H. George
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- Evaluating a sodium dispersion reagent for the Bouveault-Blanc reduction of esters
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A new sodium dispersion reagent has been evaluated for the reduction of esters. Na-D15, a sodium dispersion with sodium particle size of 5-15 μm, is a nonpyrophoric reagent that can be handled in air. In this study, a broad range of aliphatic ester substrates were reduced to primary alcohols by Na-D15/i-PrOH with good yields. The method compares favorably with modern metal hydride reductions and is much safer and efficient than the traditional Bouveault-Blanc reduction.
- An, Jie,Work, D. Neil,Kenyon, Craig,Procter, David J.
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- Transfer-hydrogenation reactions of ketones/aldehydes in water using first generation ruthenium indenylidene olefin metathesis catalyst: One step towards sequential cross-metathesis/transfer hydrogenation reactions
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The transfer hydrogenation reactions of various ketones/aldehydes and one-pot cross-metathesis/transfer hydrogenation (CM/TH) reactions of 10-undecenal were carried out in water media using first generation ruthenium-indenylidene complex (M1). A stable emulsion with an average particle size of 23.00 (±7.20) nm was formed in water media using non-ionic (Tween 20) and cationic (dodecyltrimethylammonium chloride) surfactants in the presence of acetophenone, M1 (1%) and sodium formate, yielding corresponding alcohol derivatives in quantitative yields. The performance of M1 (5%) was tested on sequential cross-metathesis/transfer hydrogenation reaction of 10-undecenal using methyl acrylate as the cross-metathesis partner in water. The sequential CM/TH reaction of 10-undecenal was found to proceed even in tap water under air atmosphere using micellar catalyst system, giving the corresponding CM/TH product in 65% yield.
- ?ztürk, Bengi ?zgün,?ztürk, Sinem
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- Hydrosilylation of aldehydes and ketones catalyzed by half-sandwich manganese(I) N-heterocyclic carbene complexes
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Easily available manganese(I) N-heterocyclic carbene (NHC) complexes, Cp(CO)2Mn(NHC), obtained in one step from industrially produced cymantrene, were evaluated as pre-catalysts in the hydrosilylation of carbonyl compounds under UV irradiation. Complexes with NHC ligands incorporating at least one mesityl group led to the most active and selective catalytic systems. A variety of aldehydes (13 examples) and ketones (11 examples) were efficiently reduced under mild conditions [Cp(CO)2Mn(IMes) (1 mol%), Ph 2SiH2 (1.5 equiv.), hν (350 nm), toluene, 25 °C, 1-24 h] with good functional group tolerance.
- Zheng, Jianxia,Elangovan, Saravanakumar,Valyaev, Dmitry A.,Brousses, Remy,Cesar, Vincent,Sortais, Jean-Baptiste,Darcel, Christophe,Lugan, Noel,Lavigne, Guy
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- REDUCTION OF ACID CHLORIDES WITH SODIUM BOROHYDRIDE IN N,N-DIMETHYLFORMAMIDE: NATURE OF THE REACTION INTERMEDIATE AND A METHOD FOR ITS CONVERSION TO THE CORRESPONDING ALDEHYDE WITH MINIMAL ALCOHOL FORMATION
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By use of sodium borohydride under the proper reaction conditions, direct conversion of both aliphatic and aromatic acid chlorides to the corresponding aldehyde can be achieved in 80-95percent yield.
- Babler, James H.,Invergo, Benedict J.
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- Cationic lipids bearing succinic-based, acyclic and macrocyclic hydrophobic domains: Synthetic studies and in vitro gene transfer
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In this communication we describe the construction of four succinic-based cationic lipids, their formulation with plasmid DNA (pDNA), and an evaluation of their in vitro gene delivery into Chinese hamster ovarian (CHO-K1) cells. The cationic lipids employed in this work possess either a dimethylamine or trimethylamine headgroup, and a macrocyclic or an acyclic hydrophobic domain composed of, or derived from two 16-atom, succinic-based acyl chains. The synthesized lipids and a co-lipid of neutral charge, either cholesterol or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), were formulated in an overall 3:2 cationic-to-neutral lipid molar ratio, then complexed with plasmid DNA (pDNA). The relative transfection performance was evaluated via a comparison between matched versus mismatched formulations defined by the rigidity relationship between the lipids employed. Gel electrophoresis was used to characterize the binding of the lipid formulations with plasmid DNA and the relative degree of plasmid degradation using a DNase I degradation assay. Small angle X-ray diffraction (SAXD) was employed to characterize the packing morphology of the lipid-DNA complexes. In general, the succinic unit embedded within the hydrophobic domain of the cationic lipids was found to improve lipid hydration. The transfection assays revealed a general trend in which mismatched formulations that employed a rigid lipid combined with a non-rigid (or flexible) lipid, outperformed the matched formulations. The results from this work suggest that the design of the cationic lipid structure and the composition of the lipoplex formulation play key roles in governing the transfection performance of nonviral gene delivery agents.
- Jubeli, Emile,Maginty, Amanda B.,Khalique, Nada Abdul,Raju, Liji,Nicholson, David G.,Larsen, Helge,Pungente, Michael D.,Goldring, William P.D.
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- Direct incorporation of hydroxy groups into isotactic polypropylene via metallocene-catalyzed copolymerization of ester group containing vinyl monomer treated with dialkylaluminum hydride and propylene
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Methyl 10-undecenoate treated with 2 equivalents of diisobutylaluminum hydride was quantitatively converted into a 10-undecenoxy aluminum compound, which was successfully utilized for metallocene-catalyzed copolymerization with propylene to produce functional polypropylene with hydroxy groups in its side chains.
- Sugimoto, Ryuichi,Matsugi, Tomoaki
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- Expedient synthesis of (R)-patulolide A
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An efficient derivation of the title compound has been formulated from easily accessible 10-undecenoic acid (1). Thus, dodec-11-en-2-ol (3), prepared from 1, was pyranylated and subjected to bromination with NBS followed by acetolysis to furnish (2E)-1-acetoxy-11-(tetrahydropyranyloxy)dodec-2-ene (5). Its hydrolysis, oxidation, and depyranylation afforded the (2E)-hydroxy ester (9). This, on Candida rugosa lipase-catalyzed acetylation, SeO2 oxidation, hydrolysis, and Yamaguchi macrolactonization, led to (R)-patulolide A (l) with 67.1% ee. The enantiomeric excess was improved to 97% by first resolving the alcohol 3 via porcine pancreatic lipase catalyzed acetylation and converting the corresponding (R)-acetate (13) to I as done above.
- Sharma,Sankaranarayanan,Chattopadhyay
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- Manganese-Catalyzed Hydrogenation of Sclareolide to Ambradiol
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The hydrogenation of (+)-Sclareolide to (?)-ambradiol catalyzed by a manganese pincer complex is reported. The hydrogenation reaction is performed with an air- and moisture-stable manganese catalyst and proceeds under relatively mild reaction conditions at low manganese and base loadings. A range of other esters could be successfully hydrogenated leading to the corresponding alcohols in good to quantitative yields using this easy-to-make catalyst. A scale-up experiment was performed leading to 99.3 % of the isolated yield of (?)-Ambradiol.
- Zubar, Viktoriia,Lichtenberger, Niels,Schelwies, Mathias,Oeser, Thomas,Hashmi, A. Stephen K.,Schaub, Thomas
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- Redox-active ligand based Mn(i)-catalyst for hydrosilylative ester reduction
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Herein a Mn(i) catalyst bearing a redox-active phenalenyl (PLY) based ligand is reported for the efficient hydrosilylation of esters to alcohols using the inexpensive silane source polymethylhydrosiloxane (PMHS) under mild conditions. Mechanistic investigations suggest a strong ligand-metal cooperation where a ligand-based single electron transfer (SET) process initiates the reaction through Si-H bond activation.
- Chakraborty, Soumi,Das, Arpan,Mandal, Swadhin K.
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supporting information
p. 12671 - 12674
(2021/12/04)
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- Micellar Catalysis for Sustainable Hydroformylation
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It is here reported a fully sustainable and generally applicable protocol for the regioselective hydroformylation of terminal alkenes, using cheap commercially available catalysts and ligands, in mild reaction conditions (70 °C, 9 bar, 40 min). The process can take advantages from both micellar catalysis and microwave irradiation to obtain the linear aldehydes as the major or sole regioisomers in good to high yields. The substrate scope is largely explored as well as the application of hydroformylation in tandem with intramolecular hemiacetalization thus demonstrating the compatibility with a broad variety of functional groups. The reaction is efficient even in large scale and the catalyst and micellar water phase can be reused at least 5 times without any impact in reaction yields. The efficiency and sustainability of this protocol is strictly related to the in situ transformation of the aldehyde into the corresponding Bertagnini's salt that precipitates in the reaction mixture avoiding organic solvent mediated purification steps to obtain the final aldehydes as pure compounds.
- Calamante, Massimo,Dei, Filippo,Maramai, Samuele,Migliorini, Francesca,Petricci, Elena
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p. 2794 - 2806
(2021/05/03)
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- Hydrosilylation of Esters Catalyzed by Bisphosphine Manganese(I) Complex: Selective Transformation of Esters to Alcohols
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Selective and efficient hydrosilylations of esters to alcohols by a well-defined manganese(I) complex with a commercially available bisphosphine ligand are described. These reactions are easy alternatives for stoichiometric hydride reduction or hydrogenation, and employing cheap, abundant, and nonprecious metal is attractive. The hydrosilylations were performed at 100 °C under solvent-free conditions with low catalyst loading. A large variety of aromatic, aliphatic, and cyclic esters bearing different functional groups were selectively converted into the corresponding alcohols in good yields.
- Bagh, Bidraha,Behera, Rakesh R.,Ghosh, Rahul,Khamari, Subrat,Panda, Surajit
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supporting information
p. 3642 - 3648
(2020/04/20)
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- Engineering Catalysts for Selective Ester Hydrogenation
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The development of efficient catalysts and processes for synthesizing functionalized (olefinic and/or chiral) primary alcohols and fluoral hemiacetals is currently needed. These are valuable building blocks for pharmaceuticals, agrochemicals, perfumes, and so forth. From an economic standpoint, bench-stable Takasago Int. Corp.'s Ru-PNP, more commonly known as Ru-MACHO, and Gusev's Ru-SNS complexes are arguably the most appealing molecular catalysts to access primary alcohols from esters and H2 (Waser, M. et al. Org. Proc. Res. Dev. 2018, 22, 862). This work introduces economically competitive Ru-SNP(O)z complexes (z = 0, 1), which combine key structural elements of both of these catalysts. In particular, the incorporation of SNP heteroatoms into the ligand skeleton was found to be crucial for the design of a more product-selective catalyst in the synthesis of fluoral hemiacetals under kinetically controlled conditions. Based on experimental observations and computational analysis, this paper further extends the current state-of-the-art understanding of the accelerative role of KO-t-C4H9 in ester hydrogenation. It attempts to explain why a maximum turnover is seen to occur starting at 25 mol % base, in contrast to only 10 mol % with ketones as substrates.
- Dub, Pavel A.,Batrice, Rami J.,Gordon, John C.,Scott, Brian L.,Minko, Yury,Schmidt, Jurgen G.,Williams, Robert F.
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p. 415 - 442
(2020/03/04)
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- Cobalt-Catalyzed C(sp2)-H Allylation of Biphenyl Amines with Unbiased Terminal Olefins
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Unactivated olefins usually react poorly in conventional alkenylation reactions. Their introduction via C-H activation is limited to aromatic acids. Herein, we disclose a C-H functionalization protocol of aromatic amines with unactivated olefins, which shows exclusive allylic selectivity for the distal ring of the biphenyl system by exploiting a readily available cobalt(II) catalyst. The allylation proceeds smoothly involving a broad set of unbiased olefins and biaryls, giving access to the functionalization of the biphenyl scaffold.
- Baccalini, Alessio,Vergura, Stefania,Dolui, Pravas,Maiti, Siddhartha,Dutta, Subhabrata,Maity, Soham,Khan, Farheen Fatima,Lahiri, Goutam Kumar,Zanoni, Giuseppe,Maiti, Debabrata
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supporting information
p. 8842 - 8846
(2019/11/11)
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- Dehydroalkylative Activation of CNN- A nd PNN-Pincer Ruthenium Catalysts for Ester Hydrogenation
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Ruthenium-pincer complexes bearing CNN- A nd PNN-pincer ligands with diethyl-or diisopropylamino side groups, which have previously been reported to be active precatalysts for ester hydrogenation, undergo dehydroalkylation on heating in the presence of tricyclohexylphosphine to release ethane or propane, giving five-coordinate ruthenium(0) complexes containing a nascent imine functional group. Ethane or propane is also released under the conditions of catalytic ester hydrogenation, and time-course studies show that this release is concomitant with the onset of catalysis. A new PNN-pincer ruthenium(0)-imine complex is a highly active catalyst for ester hydrogenation at room temperature, giving up to 15500 turnovers with no added base. This complex was shown to react reversibly at room temperature with two equivalents of hydrogen to give a ruthenium(II)-dihydride complex, where the imine functionality has been hydrogenated to give a protic amine side group. These observations have potentially broad implications for the identities of catalytic intermediates in ester hydrogenation and related transformations.
- He, Tianyi,Buttner, John C.,Reynolds, Eamon F.,Pham, John,Malek, Jack C.,Keith, Jason M.,Chianese, Anthony R.
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supporting information
p. 17404 - 17413
(2019/11/03)
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- Diaminodiphosphine tetradentate ligand and ruthenium complex thereof, and preparation methods and applications of ligand and complex
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The invention discloses a diaminodiphosphine tetradentate ligand and a ruthenium complex thereof, and preparation methods and applications of the ligand and the complex, and provides a ruthenium complex represented by a formula I, wherein L is a diaminodiphosphine tetradentate ligand represented by a formula II, and X and Y are respectively and independently chlorine ion, bromine ion, iodine ion,hydrogen negative ion or BH4. According to the present invention, the ruthenium complex exhibits excellent catalytic activity in the catalytic hydrogenation reactions of ester compounds, has high yield and high chemical selectivity, is compatible with conjugated and non-conjugated carbon-carbon double bond, carbon-carbon triple bond, epoxy, halogen, carbonyl and other functional groups, and hasgreat application prospects.
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Paragraph 0316-0319
(2019/11/04)
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- Method used for reduction of tertiary amide into alcohols and/or amines
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The invention discloses a method used for reduction of tertiary amide into alcohols and/or amines. The method comprises following steps: tertiary amide, an alkali metal reagent, and a proton donor agent are added into an organic solvent for a following reaction selectively: when the proton donor agent is a raw material alcohol and/or inorganic salt aqueous solution, the reaction product is an alcohol compound and/or tertiary amine compound. The method is capable of realizing selective reduction of tertiary amide into alcohols and tertiary amine compounds, the yield is high, the suitable rangeis wide, operation is safe and simple, the adopted raw materials are cheap and easily available; no precious metal catalyst, toxic silanes, and flammable and combustible metal hydrides are adopted; notoxic by product is generated; reaction is more friendly to the environment; problems in the prior art that amide compound reducing method operation is complex, conditions are strict, and control ofproducts is difficult are solved.
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Paragraph 0223-0226
(2019/08/07)
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- Hydrofunctionalization of Olefins to Higher Aliphatic Alcohols via Visible-Light Photocatalytic Coupling
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Abstract: An atomically economical green protocol for the hydrofunctionalization of olefins to higher aliphatic alcohols with 100% anti-Markovnikov regioselectivity was developed via visible-light photocatalytic coupling. This method employs cheap, readily available and abundant methanol as both the C1 feedstock and the hydrogen source under visible light irradiation over CdS photocatalyst. A wide scope of olefin substrates could be hydrofunctionalized successfully to the corresponding higher alcohols with high selectivity. Besides alcohol, acetone and acetonitrile can also couple with olefins to generate the corresponding hydrofunctionalization products, suggesting promising potential industrial application. Graphical Abstract: [Figure not available: see fulltext.] Hydrofunctionalization of olefins to value-added chemicals with high selectivity was achieved via visible-light photocatalytic cross-coupling.
- Bao, Jingxian,Fan, Yonghui,Zhang, Shuyi,Zhong, Liangshu,Wu, Minghong,Sun, Yuhan
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- Hydrofunctionalization of olefins to value-added chemicals: Via photocatalytic coupling
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A green strategy was developed for the synthesis of various value-added chemicals using methanol, acetonitrile, acetic acid, acetone and ethyl acetate as the hydrogen source by coupling them with olefins over heterogeneous photocatalysts. A radical coupling mechanism was proposed for the hydrofunctionalization of olefins with methanol to higher aliphatic alcohols over the Pt/TiO2 catalyst as the model reaction. C-H bond cleavage and C-C bond formation between photogenerated radicals and terminal olefins were accomplished in a single reaction at high efficiency. Our approach is atomically economical with high anti-Markovnikov regioselectivity and promising application potential under mild reaction conditions.
- Fan, Yonghui,Li, Shenggang,Bao, Jingxian,Shi, Lei,Yang, Yanzhang,Yu, Fei,Gao, Peng,Wang, Hui,Zhong, Liangshu,Sun, Yuhan
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supporting information
p. 3450 - 3456
(2018/08/06)
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- An Engineered Self-Sufficient Biocatalyst Enables Scalable Production of Linear α-Olefins from Carboxylic Acids
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Fusing the decarboxylase OleTJE and the reductase domain of P450BM3 creates a self-sufficient protein, OleT-BM3R, which is able to efficiently catalyze oxidative decarboxylation of carboxylic acids into linear α-olefins (LAOs) under mild aqueous conditions using O2 as the oxidant and NADPH as the electron donor. The compatible electron transfer system installed in the fusion protein not only eliminates the need for auxiliary redox partners, but also results in boosted decarboxylation reactivity and broad substrate scope. Coupled with the phosphite dehydrogenase-based NADPH regeneration system, this enzymatic reaction proceeds with improved product titers of up to 2.51 g L-1 and volumetric productivities of up to 209.2 mg L-1 h-1 at low catalyst loadings (～0.02 mol%). With its stability and scalability, this self-sufficient biocatalyst offers a nature-friendly approach to deliver LAOs.
- Lu, Chen,Shen, Fenglin,Wang, Shuaibo,Wang, Yuyang,Liu, Juan,Bai, Wen-Ju,Wang, Xiqing
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p. 5794 - 5798
(2018/06/01)
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- Reduction and Reductive Deuteration of Tertiary Amides Mediated by Sodium Dispersions with Distinct Proton Donor-Dependent Chemoselectivity
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A practical and scalable single electron transfer reduction mediated by sodium dispersions has been developed for the reduction and reductive deuteration of tertiary amides. The chemoselectivity of this method highly depends on the nature of the proton donor. The challenging reduction via C-N bond cleavage has been achieved using Na/EtOH, affording alcohol products, while the use of Na/NaOH/H2O leads to the formation of amines via selective C-O scission. Sodium dispersions with high specific surface areas are crucial to obtain high yields and good chemoselectivity. This new method tolerates a range of tertiary amides. Moreover, the corresponding reductive deuterations mediated by Na/EtOD-d1 and Na/NaOH/D2O afford useful α,α-dideuterio alcohols and α,α-dideuterio amines with an excellent deuterium content.
- Zhang, Bin,Li, Hengzhao,Ding, Yuxuan,Yan, Yuhao,An, Jie
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p. 6006 - 6014
(2018/05/24)
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- Cu-Catalyzed Hydroxymethylation of Unactivated Alkyl Iodides with CO To Provide One-Carbon-Extended Alcohols
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We have developed a reductive carbonylation method by which unactivated alkyl iodides can be hydroxymethylated to provide one-carbon-extended alcohol products under Cu-catalyzed conditions. The method is tolerant of alkyl β-hydrogen atoms, is robust towards a wide variety of functional groups, and was applied to primary, secondary, and tertiary alkyl iodide substrates. Mechanistic experiments indicate that the transformation proceeds by atom-transfer carbonylation (ATC) of the alkyl iodide followed in tandem by two CuH-mediated reductions in rapid succession. This radical mechanism renders the Cu-catalyzed system complementary to precious-metal-catalyzed reductive carbonylation reactions.
- Zhao, Siling,Mankad, Neal P.
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supporting information
p. 5867 - 5870
(2018/04/17)
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- Bio-based α,ω-Functionalized Hydrocarbons from Multi-step Reaction Sequences with Bio- and Metallo-catalysts Based on the Fatty Acid Decarboxylase OleTJE
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OleT from Jeotgalicoccus sp. ATCC 8456 catalyzes the decarboxylation of ω-functionalized fatty acids to the corresponding alkenols, which can themselves serve as starting material for the synthesis of polymers and fine chemicals. To show the versatility of possible reactions, a series of in vitro reaction cascades was developed where an alkenol produced by the decarboxylation of ω-hydroxy fatty acids can be further converted into alkenylamines and diols. By coupling OleT with an alcohol dehydrogenase or alcohol oxidase as well as an amino-transaminase, an oxidative decarboxylation followed by the oxidation of the terminal alcohol and a subsequent reductive transamination could be carried out. By using different cofactors or electron sources, the reactions could be performed sequentially or simultaneously. The combination of enzymatic decarboxylation with a ruthenium catalyst in a chemo-enzymatic cascade provides a novel way to synthesize long-chain diols.
- Bojarra, Samiro,Reichert, Dennis,Grote, Marius,Baraibar, álvaro Gómez,Dennig, Alexander,Nidetzky, Bernd,Mügge, Carolin,Kourist, Robert
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p. 1192 - 1201
(2018/02/13)
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- Non-Pincer-Type Manganese Complexes as Efficient Catalysts for the Hydrogenation of Esters
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Catalytic hydrogenation of carboxylic acid esters is essential for the green production of pharmaceuticals, fragrances, and fine chemicals. Herein, we report the efficient hydrogenation of esters with manganese catalysts based on simple bidentate aminophosphine ligands. Monoligated Mn PN complexes are particularly active for the conversion of esters into the corresponding alcohols at Mn concentrations as low as 0.2 mol % in the presence of sub-stoichiometric amounts of KOtBu base.
- van Putten, Robbert,Uslamin, Evgeny A.,Garbe, Marcel,Liu, Chong,Gonzalez-de-Castro, Angela,Lutz, Martin,Junge, Kathrin,Hensen, Emiel J. M.,Beller, Matthias,Lefort, Laurent,Pidko, Evgeny A.
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supporting information
p. 7531 - 7534
(2017/06/13)
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- Selective hydrogenation of unsaturated carbonyls by Ni-Fe-based alloy catalysts
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Ni-Fe alloy catalysts prepared by a simple hydrothermal method and subsequent H2 treatment exhibited the greatest activity and selectivity for the hydrogenation of biomass-derived furfural to furfuryl alcohol among the examined second metals, such as Al, Ga, In, Co, and Ti. This work reveals that the alloying of Ni and Fe is a key factor in achieving highly selective hydrogenation of the CO moiety in unsaturated carbonyl substrates. We found that decreasing the temperature of H2 treatment (i.e. decreasing the crystallite size), e.g. Ni-Fe(2)HT-573 K (TOF = 952 h-1), increased the activity compared to that over Ni-Fe(2)HT-673 (TOF = 375 h-1) for furfural hydrogenation. This result suggests that a low-coordinated Ni-Fe alloy was imperative for the catalytic cycle. Moreover, the effect of the metal/support interface was critical; despite the high catalytic performance of Ni-Fe/TiO2, Ni-Fe/Al2O3, and Ni-Fe/CeO2, Ni-Fe supported on SiO2, taeniolite, and hydrotalcite catalysts were ineffective. Vibrational studies using FT-IR measurement confirmed that furfural was physically adsorbed on the surface of the Ni-Fe alloy catalyst via an η1(O) configuration. The synthetic scope of the Ni-Fe catalytic system was very broad; various types of unsaturated carbonyls, such as unsaturated aromatics, unconjugated aliphatics, and a large substituent, were selectively converted into the corresponding unsaturated alcohols.
- Putro, Wahyu S.,Kojima, Takashi,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
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p. 3637 - 3646
(2017/08/21)
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- Catalytic Ester Metathesis Reaction and Its Application to Transfer Hydrogenation of Esters
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We report a Ru-complex-catalyzed ester metathesis reaction where an unsymmetrical ester such as ethyl hexanoate can be transformed to a mixture of starting material, hexyl ethanoate, ethyl acetate, and hexyl hexanoate in equal proportions, as expected from a classical metathesis reaction with 0.2 mol % catalyst. A 20× excess of low boiling alcohol, such as ethanol, allows for the transfer of an acyl moiety to the sacrificial low boiling ethyl acetate product, while significantly increasing the functional group tolerance and substrate scope; yields of alcohols can reach 90%, which represents an attractive alternative to current high H2 pressure hydrogenation protocols for Ru-based ester reduction chemistry. Both reactions have not been reported previously in the field of Ru-catalyzed transformations of the ester functionality.
- Dubey, Abhishek,Khaskin, Eugene
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p. 3998 - 4002
(2016/07/06)
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- A General, Practical Triethylborane-Catalyzed Reduction of Carbonyl Functions to Alcohols
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A combination of the abundant and low-cost triethylborane and sodium alkoxide generates a highly efficient catalyst for reduction of esters, as well as ketones and aldehydes, to alcohols using an inexpensive hydrosilane under mild conditions. The catalyst system exhibits excellent chemoselectivity and a high level of functional group tolerance. Mechanistic studies revealed a resting state of sodium triethylalkoxylborate that is the product of the reaction of BEt3 with sodium alkoxide. This borate species reacts with hydrosilane to form NaBEt3H, which rapidly reduces esters.
- Peng, Dongjie,Zhang, Mintao,Huang, Zheng
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supporting information
p. 14737 - 14741
(2015/10/19)
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- PROCESS FOR THE CHEMOSELECTIVE REDUCTION OF TERMINALLY SATURATED CARBOXYLIC ESTERS
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The chemoselective reduction of a carboxylic ester (I) to an alcohol by catalytic hydrogenation, in particular in the presence of a transition metal complex, more particularly in the presence of a ruthenium (II) complex is described.
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Paragraph 0066; 0067
(2015/06/10)
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- HYDROGENATION OF ESTERS WITH FE/TRIDENTATE LIGANDS COMPLEXES
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The present invention relates to the field of catalytic hydrogenation and, more particularly, to the use of Fe complexes with tridentate ligands, having one amino or imino coordinating group and two phosphino coordinating groups, in hydrogenation processes for the reduction of ketones, aldehydes, esters or lactones into the corresponding alcohol or diol, respectively.
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Page/Page column 19; 20
(2015/07/07)
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- Organoborane-Catalyzed Hydrogenation of Unactivated Aldehydes with a Hantzsch Ester as a Synthetic NAD(P)H Analogue
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We have developed a method for the hydrogenation of unactivated aldehydes, using a Hantzsch ester as a NAD(P)H analogue in the presence of an electron-deficient triarylborane as a Lewis acid catalyst. Thus, tris[3,5-bis(trifluoromethyl)phenyl]borane efficiently catalyzes the hydrogenation of aliphatic aldehydes with a Hantzsch ester in 1,4-dioxane at 100 °C to give the corresponding aliphatic primary alcohols in up to 97% yield. Aromatic aldehydes also undergo the hydrogenation, even at 25 °C, to furnish the corresponding aromatic primary alcohols in up to 100% yield.
- Hamasaka, Go,Tsuji, Hiroaki,Uozumi, Yasuhiro
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supporting information
p. 2037 - 2041
(2015/09/01)
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- Chemoselective hydrogenation and transfer hydrogenation of aldehydes catalyzed by iron(II) PONOP pincer complexes
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Iron-catalyzed hydrogenation has drawn much attention, yet the scope and chemoselectivity of iron catalysis warrant further improvement. Here we report new iron pincer complexes as chemoselective hydrogenation and transfer hydrogenation catalysts. Several Fe(II) complexes supported by a 2,6-bis(phosphinito)pyridine ligand (PONOP) have been synthesized. Fe(II) hydride complexes [(iPrPONOP)Fe(CO)(H)Br] (2) and [(iPrPONOP)Fe(CO)(H)(CH3CN)](OTf) (3) can activate H2 at room temperature. Complexes 2 and 3 are hydrogenation catalysts at room temperature, and the hydrogenation is selective for aldehyde in the presence of ketone and alkene groups. 2 and 3 are also chemoselective transfer hydrogenation catalysts using sodium formate as the hydride source.
- Mazza, Simona,Scopelliti, Rosario,Hu, Xile
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supporting information
p. 1538 - 1545
(2015/05/13)
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- Intramolecular hydroalkoxylation catalyzed inside a self-assembled cavity of an enzyme-like host structure
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Self-assembled resorcin[4]arene hexamer catalyzes the intramolecular hydroalkoxylation of unsaturated alcohols to the corresponding cyclic ethers under mild conditions. The mode of catalysis and encapsulation-based substrate selectivity of the host efficiently mimic the basic principle of operation observed in enzymes.
- Catti,Tiefenbacher
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supporting information
p. 892 - 894
(2015/02/05)
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- COMPLEX CATALYSTS BASED ON AMINO-PHOSPHINE LIGANDS FOR HYDROGENATION AND DEHYDROGENATION PROCESSES
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The present application discloses novel PWNN and PWNWP metal catalysts for organic chemical syntheses including hydrogenation (reduction) of unsaturated compounds or dehydrogenation of substrates. The range of hydrogenation substrate compounds includes esters, lactones, enals, enones, enolates, oils and fats, resulting in alcohols, enols, diols, and triols as reaction products. The catalysts of current application can be used to catalyze a hydrogenation reaction under solvent free conditions. The present catalysts also allow the hydrogenation to proceed without added base, and it can be used in place of the conventional reduction methods employing hydrides of the main-group elements. Furthermore, the catalysts of the present application can catalyze a dehydrogenation reaction under homogenous and/or acceptorless conditions. As such, the catalysts provided herein can be useful in substantially reducing cost and improving the environmental profile of manufacturing processes for a variety of chemicals.
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Page/Page column 38; 39
(2014/09/29)
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- Chemoselective ruthenium-catalysed reduction of carboxylic acids
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A very general and efficient catalytic protocol for the selective reduction of carboxylic acids to their corresponding alcohols under mild conditions is described. Various carboxylic acids, including benzoic acids, were reduced in good yields using the presented methodology. The ruthenium-catalysed method yields a highly chemoselective reduction permitting the reduction of a carboxylic acid functionality in the presence of numerous other potentially reducible moieties.
- Fernandez-Salas, Jose A.,Manzini, Simone,Nolan, Steven P.
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supporting information
p. 308 - 312
(2014/05/20)
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- Highly chemoselective reduction of amides (primary, secondary, tertiary) to alcohols using SmI2/amine/H2O under mild conditions
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Highly chemoselective direct reduction of primary, secondary, and tertiary amides to alcohols using SmI2/amine/H2O is reported. The reaction proceeds with C-N bond cleavage in the carbinolamine intermediate, shows excellent functional group tolerance, and delivers the alcohol products in very high yields. The expected C-O cleavage products are not formed under the reaction conditions. The observed reactivity is opposite to the electrophilicity of polar carbonyl groups resulting from the nX → πC=O (X = O, N) conjugation. Mechanistic studies suggest that coordination of Sm to the carbonyl and then to Lewis basic nitrogen in the tetrahedral intermediate facilitate electron transfer and control the selectivity of the C-N/C-O cleavage. Notably, the method provides direct access to acyl-type radicals from unactivated amides under mild electron transfer conditions.
- Szostak, Michal,Spain, Malcolm,Eberhart, Andrew J.,Procter, David J.
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supporting information
p. 2268 - 2271
(2014/03/21)
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- SELECTIVE HYDROGENATION OF ALDEHYDE WITH RU/BIDENTATE LIGANDS COMPLEXES
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The present invention relates to processes for the reduction by hydrogenation, using molecular H2, of a C5-C20 substrate containing one or two aldehydes functional groups into the corresponding alcohol or diol, characterized in that said process is carried out in the presence of —at least one catalyst or pre-catalyst in the form of a ruthenium complex having a coordination sphere of the N2P2O2, wherein the coordinating atoms N2 are provided by a first bidentate ligand, the coordinating atoms P2 are provided by a second bidentate ligand and the coordinating atoms O2 are provided by two non-linear carboxylate ligands; and —optionally of an acidic additive.
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Paragraph 0207
(2014/09/03)
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- Facile and efficient KOH-catalysed reduction of esters and tertiary amides
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Esters and tertiary amides were efficiently reduced to their corresponding alcohols and amines in high yields under mild and environmentally friendly conditions. The presented KOH-catalysed system involves a simple hydrosilylation procedure that is carried out under solvent-free conditions and does not require the use of inert conditions.
- Fernandez-Salas, Jose A.,Manzini, Simone,Nolan, Steven P.
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supporting information
p. 9758 - 9760
(2013/10/21)
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- PROCESS FOR THE CHEMOSELECTIVE REDUCTION OF TERMINALLY SATURATED CARBOXYLIC ESTERS
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The chemoselective reduction of a carboxylic ester (I) to an alcohol by catalytic hydrogenation, in particular in the presence of a transition metal complex, more particularly in the presence of a ruthenium (II) complex is described.
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Page/Page column 13
(2013/12/03)
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- A convenient nickel-catalysed hydrosilylation of carbonyl derivatives
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Hydrosilylation of aldehydes and ketones catalysed by nickel acetate and tricyclohexylphosphine as the catalytic system was demonstrated using polymethylhydrosiloxane as a cheap reducing reagent. The Royal Society of Chemistry 2013.
- Zheng, Jianxia,Darcel, Christophe,Sortais, Jean-Baptiste
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- Unexpected role of anionic ligands in the ruthenium-catalyzed base-free selective hydrogenation of aldehydes
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Bigger and better: The replacement of anionic chloride ligands in Noyori-type [(diamine)(diphosphine)RuCl2] catalysts with bulky carboxylate ligands enabled the efficient selective hydrogenation of a variety of aldehydes under base-free conditions (see scheme). Turnover numbers of up to 100 000 were reached in the presence of a bulky carboxylic acid co-catalyst. This type of catalytic system probably operates through an inner-sphere mechanism. Copyright
- Dupau, Philippe,Bonomo, Lucia,Kermorvan, Laurent
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supporting information
p. 11347 - 11350
(2013/11/06)
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- Iron-catalyzed hydrosilylation of esters
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The first hydrosilylation of esters catalyzed by a well defined iron complex has been developed. Esters are converted to the corresponding alcohols at 100 °C, under solvent-free conditions and visible light activation. Copyright
- Bezier, David,Venkanna, Gopaladasu T.,Castro, Luis C. Misal,Zheng, Jianxia,Roisnel, Thierry,Sortais, Jean-Baptiste,Darcel, Christophe
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supporting information; experimental part
p. 1879 - 1884
(2012/09/22)
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- Total synthesis and antifungal activity of (2S,3R)-2-aminododecan-3-ol
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We report the total synthesis of (2S,3R)-2-aminododecan-3-ol has been achieved starting from commercially available 10-undecenoic acid. The key steps involved are Sharpless asymmetric epoxidation, Miyashita's boron-directed C-2 regioselective azidolysis, generated the asymmetric centers and in situ detosylation and reduction of azido tosylate. The antifungal activity of the synthesized (2S,3R)-2-aminododecan-3-ol was evaluated on several Candida strains and was comparable to miconazole, a standard drug.
- Vijai Kumar Reddy,Prabhavathi Devi,Prasad,Poornima,Ganesh Kumar
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supporting information; experimental part
p. 4678 - 4680
(2012/08/07)
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- Electron transfer reduction of carboxylic acids using SmI 2-H2O-Et3N
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The first general method for efficient electron transfer reduction of carboxylic acids has been developed. The protocol using SmI2 - H 2O - Et3N allows for reduction of a variety of carboxylic acids in excellent yields and provides an attractive alternative to processes mediated by reactive alkali metals, lithium aluminum hydride, and boron hydrides. Of broader significance, the method allows acyl radical equivalents to be generated from carboxylic acids under mild reaction conditions.
- Szostak, Michal,Spain, Malcolm,Procter, David J.
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supporting information; experimental part
p. 840 - 843
(2012/04/11)
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- Synthesis and characterization of some novel higher C,N-diphenyl nitrones, isoxazolines, and mercaptobenzimidazoles as oleochemicals
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Some novel long-chain nitrones, isoxazolines, and (1H-benzo[d]-imidazol-2- ylthio) derivatives were synthesized. Nitrones, N-{4-[2-(tetradecylthio)acetoxy] benzylidene}aniline oxide, and N-[4-(12-oxo-2,5,8,11-tetraoxadocosan-22-yloxy) benzylidene]aniline oxide were prepared via the reaction of -phenylhydroxylamine with the corresponding aromatic aldehydes. The isoxazolines were prepared from undec-10-en-1-ol and benzonitrile-N-oxide which was generated in situ. The 1H-benzo[d]-imidazol-2-ylthio derivatives were synthesized via the replacement reaction of -bromo esters and 2-mercaptobenzimidazole.
- Yldrm,Cetin
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experimental part
p. 952 - 964
(2012/08/07)
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- Preparation of samarium(II) iodide: Quantitative evaluation of the effect of water, oxygen, and peroxide content, preparative methods, and the activation of samarium metal
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Samarium(II) iodide (SmI2) is one of the most important reducing agents in organic synthesis. Synthetic chemistry promoted by SmI2 depends on the efficient and reliable preparation of the reagent. Unfortunately, users can experience difficulties preparing the reagent, and this has prevented realization of the full synthetic potential of SmI2. To provide synthetic chemists with general and reliable methods for the preparation of SmI2, a systematic evaluation of the factors involved in its synthesis has been carried out. Our studies confirm that SmI2 is a user-friendly reagent. Factors such as water, oxygen, and peroxide content in THF have little influence on the synthesis of SmI2. In addition, the use of specialized glovebox equipment or Schlenk techniques is not required for the preparation of SmI2. However, our studies suggest that the quality of samarium metal is an important factor and that the use of low quality metal is the main cause of failed preparations of the reagent. Accordingly, we report a straightforward method for activation of "inactive" samarium metal and demonstrate the broad utility of this protocol through the electron transfer reductions of a range of substrates using SmI2 prepared from otherwise "inactive" metal. An investigation into the stability of SmI2 solutions and an evaluation of commercially available solutions of the reagent is also reported.
- Szostak, Michal,Spain, Malcolm,Procter, David J.
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supporting information; experimental part
p. 3049 - 3059
(2012/06/01)
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- Indium tri(isopropoxide)-catalyzed selective Meerwein-Ponndorf-Verley reduction of aliphatic and aromatic aldehydes
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Indium tri(isopropoxide)-catalyzed Meerwein-Ponndorf-Verley reduction of aliphatic and aromatic aldehydes in 2-propanol gave selectively the corresponding primary alcohols in good to excellent yields at room temperature. A wide range of functional groups including alkene, ether, ketone, ester, nitrile, and nitro were tolerated under the optimum reaction conditions. Chemoselective reductions were also achieved not only between aromatic aldehyde, aromatic ketone, and epoxide but also between aliphatic aldehyde and alkene.
- Lee, Jaeyoung,Ryu, Taekyu,Park, Sangjune,Lee, Phil Ho
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supporting information; experimental part
p. 4821 - 4825
(2012/07/03)
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- Hydrosilylation of aldehydes and ketones catalyzed by an n-heterocyclic carbene-nickel hydride complex under mild onditions
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Half-sandwich N-heterocyclic carbene (NHC)-nickel complexes of the general formula [NiACHTUNGTRENUNG(NHC)ClCp?] (Cp?= Cp, Cp*) efficiently catalyze the hydrosilylation of aldehydes and ketones at room temperature in the presence of a catalytic amount of sodium triethylborohydride and thus join the fairly exclusive club of well-defined nickel(II) catalyst precursors for the hydrosilylation of carbonyl functionalities. Of notable interest is the isolation of an intermediate nickel hydride complex that proved to be the real catalyst precursor.
- Bheeter, Linus P.,Henrion, Mickael,Brelot, Lydia,Darcel, Christophe,Chetcuti, Michael J.,Sortais, Jean-Baptiste,Ritleng, Vincent
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supporting information
p. 2619 - 2624
(2013/01/15)
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- Cyclopentadienyl-NHC iron complexes for solvent-free catalytic hydrosilylation of aldehydes and ketones
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Seven cyclopentadienyl-NHC piano-stool iron complexes were prepared and studied in the catalytic hydrosilylation of aldehydes and ketones under visible light irradiation. A significant acceleration of the rate was observed when the reactions were carried out under solvent-free conditions. Single-crystal X-ray structural analyses were performed for complexes 5 and 7. Cp-NHC piano-stool iron complexes were found to be efficient catalysts for the hydrosilylation of aldehydes and ketones under solvent-free conditions and by activation by light irradiation. An acceleration of the rate of the reaction was observed under neat conditions relative to those for the reactions in toluene or THF.
- Bezier, David,Jiang, Fan,Roisnel, Thierry,Sortais, Jean-Baptiste,Darcel, Christophe
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p. 1333 - 1337
(2012/05/20)
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- Silver(I)-Catalyzed deprotection of p -methoxybenzyl ethers: A mild and chemoselective method
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The p-methoxybenzyl protecting group (PMB) on various alcohols and an acid was efficiently and selectively cleaved by the action of a catalytic amount of silver(I) hexafluoroantimonate combined with 0.5 equiv of 1,3,5- trimethoxybenzene in dichloromethane at 40 °C.
- Kern, Nicolas,Dombray, Thomas,Blanc, Aurelien,Weibel, Jean-Marc,Pale, Patrick
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p. 9227 - 9235,9
(2012/12/12)
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- Nickel phosphide nanocatalysts for the chemoselective hydrogenation of alkynes
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Well-defined 25 nm nickel phosphide nanoparticles act as a colloidal catalyst for the chemoselective hydrogenation of terminal and internal alkynes. Cis-alkenes are obtained in mild conditions with good conversion and selectivity. The phosphorus inserted in the Ni-P nanoparticles is critical for the selectivity of the nanocatalyst. Mechanistic investigations using isotope labeling provide insight on the reactants interaction with the nanoparticles surface. They pinpoint the occurrence of CH bond cleavage in terminal alkynes during the reaction.
- Carenco, Sophie,Leyva-Pérez, Antonio,Concepción, Patricia,Boissire, Cédric,Mézailles, Nicolas,Sanchez, Clément,Corma, Avelino
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experimental part
p. 21 - 28
(2012/07/27)
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- InBr3-catalyzed deoxygenation of carboxylic acids with a hydrosilane: Reductive conversion of aliphatic or aromatic carboxylic acids to primary alcohols or diphenylmethanes
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A simple and practical procedure for the direct reduction of aliphatic carboxylic acids with a variety of functional groups to a primary alcohol using the mild reducing reagent tetramethyldisiloxane (TMDS), in the presence of a catalytic amount of InBr3 has been developed. This simple reducing system, when used together with a hydrosilane, allows the preparation of the diphenylmethane derivative directly from an aromatic carboxylic acid and an aromatic compound. Copyright
- Sakai, Norio,Kawana, Keita,Ikeda, Reiko,Nakaike, Yumi,Konakahara, Takeo
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experimental part
p. 3178 - 3183
(2011/06/28)
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