112-30-1Relevant articles and documents
Process Development for the Rhodium-Catalyzed Reductive Amination in a Thermomorphic Multiphase System
Künnemann, Kai U.,Bianga, Jonas,Scheel, Ricarda,Seidensticker, Thomas,Dreimann, Jens M.,Vogt, Dieter
, p. 41 - 49 (2020)
For the first time, the successful application of the homogeneously catalyzed reductive amination in a thermomorphic multiphase system (TMS) and the first reported scale-up of this reaction into a continuous process, which recovers and recycles the homogeneous catalyst in flow, is presented. Herein, the model substrate 1-decanal reacts with the secondary amine diethylamine to form the corresponding product N,N-diethyldecylamine. A thermomorphic multiphase system (TMS) is established as a recycling strategy to recover and reuse the catalyst for the continuous process. After screening different solvents for the TMS and optimizing the reaction conditions in batch mode, the recycling of the rhodium catalyst was realized in a fully automated miniplant. Parameters influencing the stability of the process were identified and optimized to develop the continuous process. The process was operated in a steady state over 90 h with yields >90% of the desired product and low catalyst leaching 1%/h.
Reduction of aldehydes using trialkylboranes in ionic liquids
Kabalka,Malladi
, p. 2191 - 2191 (2000)
Non-aqueous ionic liquids, molten salts, have been found to enhance organoboron mediated reductions of aldehydes.
Oxidation of sterically hindered alkoxysilanes and phenylsilanes under basic conditions
Smitrovich, Jacqueline H.,Woerpel
, p. 6044 - 6046 (1996)
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Selective Removal of the Methyldiphenylsilyl Protecting Group Using Azide Ion
Monger, Steven J.,Parry, David M.,Roberts, Stanley M.
, p. 381 - 382 (1989)
Sodium azide in dimethylformamide effects the cleavage of the methyldiphenylsilyl ether bond under conditions whereby t-butyldimethylsilyl ethers and t-butyldiphenylsilyl ethers are stable.
Structure sensitivity in the ruthenium nanoparticle catalyzed aqueous-phase Fischer-Tropsch reaction
Quek, Xian-Yang,Pestman, Robert,Van Santen, Rutger A.,Hensen, Emiel J. M.
, p. 3510 - 3523 (2014)
Low-temperature Fischer-Tropsch reaction data are reported for Ru nanoparticles suspended in the water phase. Their activity and selectivity strongly depends on particle size, when varied between 1 to 5 nm. Small particles display high oxygenates selectivity. The Anderson-Schulz-Flory (ASF) chain-growth probability for oxygenates is significantly lower than that observed for hydrocarbons. The chain growth parameter for hydrocarbon formation is independent of particle size. For oxygenates it is constant only for particles larger than 3 nm. Oxygenate and hydrocarbon formation occur on different sites. The ASF chain-growth probability for oxygenate formation increases with temperature. For very small 1.2 nm particles it shows a maximum as a function of temperature. This unusual temperature dependence is due to relatively slow CO dissociation compared to the rate of C-C bond formation. This journal is
Deprotection of benzyl ethers using 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) under photoirradiation
Rahim, Mohammad Abdur,Matsumura, Shuichi,Toshima, Kazunobu
, p. 7307 - 7309 (2005)
The deprotection of benzyl ethers was effectively realized in the presence of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in MeCN under photoirradiation using a long wavelength UV light.
Reactions of Amino Acid Decyl Esters with Nucleophiles Catalyzed by Polymer-Supported Amine-Metal Complexes
Ohtani, Noritaka,Inoue, Yukihiko,Inagaki, Yuichi,Fukuda, Kenji,Nishiyama, Taisuke
, p. 1669 - 1676 (1995)
The reactions of alanine decyl ester (AlaODc) with nucleophiles were catalyzed by a crosslinked polystyrene-supported ethylenediamine-copper(II) ion complex (Cu en-PS) under toluene/resin two-phase conditions or toluene/ aqueous buffer/resin three-phase conditions.In the two-phase reactions with octylamine, the rate was increased with a decreasing metal content of the resin.The catalytic efficiency was also dependent on other factors, that is, metal ion, ligand structure, and substrate structure.In the three-phase reactions with water, the hydrolysis was very fast when acetate ions were present in the aqueous phase.It has been suggested that the reactions proceed via a substrate-coordinated intermediate complex under both conditions.
THERMAL STABILITY IN RELATION TO HYDROLYSIS OF SODIUM DECYLSULPHATE IN A SOLUTION WITH NEMATIC LYOTROPIC PROPERTIES.
Hochapfel,Boidart,Laurent
, p. 201 - 209 (1981)
Studied the effect of temperature as a function of time on sodium decylsulphate in the ternary nematic solution first proposed by Radley and Reeves. The hydrolysis of the ester was followed by recording the pH-profile and by determining the liberated decanol. It was found that the ester was subject to slow uncatalyzed hydrolysis in the beginning and to much faster acid catalyzed hydrolysis later on. The decylsulphate underwent insignificant cleavage over 48 hours up to at least 70 degree C with perfect retention of the nematic phase. The results showed that the chemical stability was as good as that of many thermotropic compounds.
Novel deprotection of SEM ethers: A very mild and selective method using magnesium bromide
Vakalopoulos, Alexandros,Hoffmann
, p. 1447 - 1450 (2000)
(Matrix presented) New lability and stability sequences have been established for multifunctional substrates containing SEM ether group(s) by a MgBr2/Et2O/ MeNO2 deprotection protocol.
Hydrogenation versus hydrogenolysis with a safe, selective and reusable catalyst: Palladium black on Teflon
Belotti, Damien,Cantagrel, Guillaume,Combellas, Catherine,Cossy, Janine,Kanoufi, Frederic,Nunige, Sandra
, p. 761 - 764 (2005)
Palladium black deposit is obtained by reduction and metallization of the Teflon polymer surface of magnetic stirring bars. These stirring bars can be used to perform selective hydrogenation of olefins and acetylenic compounds whilst hydrogenolysis is not observed. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
Reduction of Aldehydes and Ketones Using Sodium Formate in 1-Methyl-2-pyrrolidinone
Babler, James H.,Sarussi, Steven J.
, p. 3367 - 3369 (1981)
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Transition metal catalysis in fluorous media: Practical application of a new immobilization principle to rhodium-catalyzed hydroborations of alkenes and alkynes
Juliette, Jerrick J. J.,Rutherford, Drew,Horváth, István T.,Gladysz
, p. 2696 - 2704 (1999)
Addition of a yellow-orange toluene solution of [Rh(C1)(COD)]2 to a colorless CF3C6F11 solution of P(CH2CH2R(f6))3 (R(f6) = (CF2)5CF3)3) gives a colorless toluene solution of COD and an orange CF3C6F11 solution of ClRh[P(CH2CH2R(f6))3]3 (1). Evaporation of CF3C6F11 gives analytically pure 1 (94%), which is insoluble in most organic solvents and stable to 300 °C. Alkenes, catecholborane, and CF3C6F11 solutions of 1 (950:950:1 mol ratio for norbomene) are stirred for 1-24 h at 40 °C (heterogeneous conditions). The resulting alkylboranes are extracted with benzene (2x; turnover number (TON) 854 (90%) for norbornene), toluene, or THF, and the catalyst solution is reused (TON 2409 for three cycles). Subsequent reactions with H202/NaOH give alcohols, which are isolated in 92-77% yields (11 examples). Longer reaction times afford TON values higher than 10000 (2CH2R(f8))3]3 (2), and the nonfluorinated analogue ClRh[P((CH2)7CH3)3]3 are similarly prepared. Solubilities and reactivities are compared. Atomic absorption analyses shows rhodium losses of 0.4% (1) and 0.2% (2) per cycle, corresponding to 4.52.2 ppm rhodium/mol of addition product. These data demonstrate the viability and practicality of an exciting new approach to catalyst immobilization. Addition of a yellow-orange toluene solution of [Rh(Cl)(COD)]2 to a colorless CF3C6F11 solution of P(CH2CH2Rf6)3 (Rf6 = (CF2)5CF3)3) gives a colorless toluene solution of COD and an orange CF3C6F11 solution of ClRh[P(CH2CH2Rf6)3]3 (1). Evaporation of CF3C6F11 gives analytically pure 1 (94%), which is insoluble in most organic solvents and stable to 300 °C. Alkenes, catecholborane, and CF3C6F11 solutions of 1 (950:950:1 mol ratio for norbornene) are stirred for 1-24 h at 40 °C (heterogeneous conditions). The resulting alkylboranes are extracted with benzene (2×; turnover number (TON) 854 (90%) for norbornene), toluene, or THF, and the catalyst solution is reused (TON 2409 for three cycles). Subsequent reactions with H2O2/NaOH give alcohols, which are isolated in 92-77% yields (11 examples). Longer reaction times afford TON values higher than 10000 (2CH2Rf8)3]3 (2), and the nonfluorinated analogue ClRh[P((CH2)7CH3)3]3 are similarly prepared. Solubilities and reactivities are compared. Atomic absorption analyses shows rhodium losses of 0.4% (1) and 0.2% (2) per cycle, corresponding to 4.5-2.2 ppm rhodium/mol of addition product. These data demonstrate the viability and practicality of an exciting new approach to catalyst immobilization.
An Immobilized Organotin Catalyst for Reduction of Ketones and Aldehydes
Matlin, Stephen A.,Gandham, Permjit S.
, p. 798 - 799 (1984)
A dialkyltin dimethoxide linked to the surface of silica functions as an efficient and readily recovered and recycled hydride transfer catalyst for the reduction of ketones and aldehydes using polymethylhydrosiloxane as the hydrogen source.
Preparation of samarium(II) iodide: Quantitative evaluation of the effect of water, oxygen, and peroxide content, preparative methods, and the activation of samarium metal
Szostak, Michal,Spain, Malcolm,Procter, David J.
, p. 3049 - 3059 (2012)
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.
Hydrogen-transfer reduction of carbonyl compounds promoted by nickel nanoparticles
Alonso, Francisco,Riente, Paola,Yus, Miguel
, p. 1847 - 1852 (2008)
Nickel(0) nanoparticles, generated from nickel(II) chloride, lithium powder and a catalytic amount of 4,4-di-tert-butylbiphenyl (DTBB) in THF at room temperature, have been found to promote the reduction of a variety of ketones and aldehydes by transfer hydrogenation using isopropanol as the hydrogen donor. The nickel nanoparticles were characterised and could be re-utilised with a good performance in the absence of a base. A mechanistic study demonstrates that the reaction proceeds through a dihydride-type mechanism.
Deoxygenative hydroboration of primary, secondary, and tertiary amides: Catalyst-free synthesis of various substituted amines
An, Duk Keun,Jaladi, Ashok Kumar,Kim, Hyun Tae,Yi, Jaeeun
, (2021/11/17)
Transformation of relatively less reactive functional groups under catalyst-free conditions is an interesting aspect and requires a typical protocol. Herein, we report the synthesis of various primary, secondary, and tertiary amines through hydroboration of amides using pinacolborane under catalyst-free and solvent-free conditions. The deoxygenative hydroboration of primary and secondary amides proceeded with excellent conversions. The comparatively less reactive tertiary amides were also converted to the corresponding N,N-diamines in moderate yields under catalyst-free conditions, although alcohols were obtained as a minor product.
Enantiomeric synthesis of natural alkylglycerols and their antibacterial and antibiofilm activities
Fernández Montoya, Deicy J.,Contreras Jordan, Luis A.,Moreno-Murillo, Bárbara,Silva-Gómez, Edelberto,Mayorga-Wandurraga, Humberto
supporting information, p. 2544 - 2550 (2019/11/13)
Alkylglycerols (AKGs) are bioactive natural compounds that vary by alkyl chain length and degree of unsaturation, and their absolute configuration is 2S. Three AKGs (5l–5n) were synthesised in enantiomerically pure form, and were characterised for the first time together with 12 other known and naturally occurring AKGs (5a–5k, 5o). Their structures were established using 1H and 13C APT NMR with 2D-NMR, ESI-MS or HRESI-MS and optical rotation data, and they were tested for their antibacterial and antibiofilm activities. AKGs 5a–5m and 5o showed activity against five clinical isolates and P. aeruginosa ATCC 15442, with MIC values in the range of 15–125 μg/mL. In addition, at half of the MIC, most of the AKGs reduced S. aureus biofilm formation in the range of 23%–99% and P. aeruginosa ATCC 15442 biofilm formation in the range of 14%–64%. The antibiofilm activity of the AKGs assessed in this work had not previously been studied.
