- Air Stable Iridium Catalysts for Direct Reductive Amination of Ketones
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Half-sandwich iridium complexes bearing bidentate urea-phosphorus ligands were found to catalyze the direct reductive amination of aromatic and aliphatic ketones under mild conditions at 0.5 mol % loading with high selectivity towards primary amines. One of the complexes was found to be active in both the Leuckart–Wallach (NH4CO2H) type reaction as well as in the hydrogenative (H2/NH4AcO) reductive amination. The protocol with ammonium formate does not require an inert atmosphere, dry solvents, as well as additives and in contrast to previous reports takes place in hexafluoroisopropanol (HFIP) instead of methanol. Applying NH4CO2D or D2 resulted in a high degree of deuterium incorporation into the primary amine α-position.
- Polishchuk, Iuliia,Sklyaruk, Jan,Lebedev, Yury,Rueping, Magnus
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supporting information
p. 5919 - 5922
(2021/03/08)
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- Ultra-small cobalt nanoparticles from molecularly-defined Co-salen complexes for catalytic synthesis of amines
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We report the synthesis of in situ generated cobalt nanoparticles from molecularly defined complexes as efficient and selective catalysts for reductive amination reactions. In the presence of ammonia and hydrogen, cobalt-salen complexes such as cobalt(ii)-N,N′-bis(salicylidene)-1,2-phenylenediamine produce ultra-small (2-4 nm) cobalt-nanoparticles embedded in a carbon-nitrogen framework. The resulting materials constitute stable, reusable and magnetically separable catalysts, which enable the synthesis of linear and branched benzylic, heterocyclic and aliphatic primary amines from carbonyl compounds and ammonia. The isolated nanoparticles also represent excellent catalysts for the synthesis of primary, secondary as well as tertiary amines including biologically relevant N-methyl amines.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Gawande, Manoj B.,Jagadeesh, Rajenahally V.,Kalevaru, Narayana V.,Kamer, Paul C. J.,Senthamarai, Thirusangumurugan,Zbo?il, Radek
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p. 2973 - 2981
(2020/03/27)
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- Selective synthesis of primary amines by reductive amination of ketones with ammonia over supported Pt catalysts
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Supported platinum catalysts are studied for the reductive amination of ketones under ammonia and hydrogen. For a model reaction with 2-adamantanone, Pt-loaded MoOx/TiO2 (Pt-MoOx/TiO2) shows the highest yield of primary amine. The catalyst is effective for the selective transformation of various aliphatic and aromatic ketones to the corresponding primary amines, which demonstrates the first example of the selective synthesis of primary amines by this reaction. The yield of the amine increases with increase in the negative shift of the C£O stretching band in the infrared spectra of adsorbed acetone on the catalysts, suggesting that Lewis acid sites on the support material play an important role in this catalytic system.
- Nakamura, Yoichi,Kon, Kenichi,Touchy, Abeda Sultana,Shimizu, Ken-Ichi,Ueda, Wataru
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p. 921 - 924
(2015/03/18)
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- N-alkylation of ammonia and amines with alcohols catalyzed by Ni-loaded CaSiO3
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Nickel nanoparticles loaded onto calcium silicate (Ni/CaSiO3) have been prepared by ion-exchange method followed by in situ H 2-reduction of the calcined precursor. Ni/CaSiO3 was found to be effective for the catalytic direct synthesis of primary amines from alcohols and NH3 under relatively mild conditions. Various aliphatic alcohols are tolerated, and the turnover number (TON) was higher than those of Ru-based homogeneous catalysts. The catalyst was recoverable and was reused. Effects of the surface oxidation states and particle size of Ni on the catalytic activity were studied by infrared (IR) investigation of the states of adsorbed CO and transmission electron microscopy (TEM). It is clarified that the surface Ni0 sites on small (3 nm) sized Ni nanoparticles are the catalytically active species. Ni/CaSiO3 was also effective for the alkylation of anilines and aliphatic amines with various alcohols (benzyl and aliphatic alcohols) under additive free conditions; primary amines were converted into secondary amines and secondary amines into tertiary amines.
- Shimizu, Ken-Ichi,Kanno, Shota,Kon, Kenichi,Hakim Siddiki,Tanaka, Hideyuki,Sakata, Yoshihisa
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p. 134 - 138
(2014/06/09)
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- Catalytic activation of hydrazine hydrate by gold nanoparticles: Chemoselective reduction of nitro compounds into amines
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Supported gold nanoparticles (2NH2 as a transfer hydrogenation agent. Aryl and alkyl nitro compounds are cleanly and selectively reduced into the corresponding amines in the presence of 4 equivalents of hydrazine. The reaction tolerates other potentially reducible functionalities such as carboxylate, carbonyl, cyano or halides which remain intact.
- Gkizis, Petros L.,Stratakis, Manolis,Lykakis, Ioannis N.
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- Heterogeneous Ni catalyst for direct synthesis of primary amines from alcohols and ammonia
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This paper reports the synthesis of primary amines from alcohols and NH3 by an Al2O3-supported Ni nanoparticle catalyst as the first example of heterogeneous and noble-metal-free catalytic system for this reaction without additional hydrogen sources under relatively mild conditions. Various aliphatic alcohols are tolerated, and turnover numbers were higher than those of Ru-based homogeneous catalysts. The catalyst was recoverable and was reused. The effects of the Ni oxidation states and the acid-base nature of support oxides on the catalytic activity are studied. It is clarified that the surface metallic Ni sites are the catalytically active species, and the copresence of acidic and basic sites on the support surface is also indispensable for this catalytic system.
- Shimizu, Ken-Ichi,Kon, Kenichi,Onodera, Wataru,Yamazaki, Hiroshi,Kondo, Junko N.
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p. 112 - 117
(2013/03/29)
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- An efficient and general synthesis of primary amines by ruthenium-catalyzed amination of secondary alcohols with ammonia
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Atom efficiency and selectivity are the key features of the first homogeneously catalyzed amination of secondary alcohols with ammonia to give the corresponding primary amines (see scheme). This novel amination method relies on the commercially available catalyst [Ru3(CO)12]/ cataCXium PCy and does not require any additional source of hydrogen.
- Imm, Sebastian,Neubert, Lorenz,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 8126 - 8129
(2011/02/22)
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- Direct amination of secondary alcohols using ammonia
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Hydrogen shuttle: For the first time secondary alcohols and ammonia can be directly converted into primary amines with a selectivity of up to 99% by using a simple ruthenium/phosphine catalyst (see scheme; R1, R2= alkyl, aryl, alkenyl; M=[Ru3(CO)12]; and L=phosphine ligand).
- Pingen, Dennis,Mueller, Christian,Vogt, Dieter
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supporting information; experimental part
p. 8130 - 8133
(2011/02/22)
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- Detritylation of N-tritylamines via a naphthalene-catalyzed lithiation process
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The reaction of aliphatic and aromatic secondary and tertiary N-tritylamines 1 with lithium powder and a catalytic amount of naphthalene led to reductive detritylation, affording the corresponding amines 2 in good to excellent yields. The trityl group could selectively be removed in the presence of an allyl or a benzyl group. The detritylation process could successfully be extended to several hydroxy, alkoxy and amino functionalized N-tritylamines. The chemoselectivity between the trityl-nitrogen and the trityl-oxygen bond cleavages was also studied. This methodology represents an efficient deprotection of N-tritylamines under nonacidic reaction conditions.
- Behloul, Cherif,Guijarro, David,Yus, Miguel
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p. 1274 - 1280
(2007/10/03)
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- Non-metallocene compounds, method for the production thereof and use of the same for the polymerisation of olefins
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The invention relates to a method for producing special transition metal compounds, to novel transition metal compounds and to the use of the same for the polymerisation of olefins.
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- Tetracyclic benzimidazole derivatives and combinatorial libraries thereof
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The present invention relates to novel tetracyclic benzimidazole derivative compounds of the following formula: wherein R1to R10have the meanings described in here. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing tetracyclic benzimidazole derivative compounds.
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- 3-amino-5-methyl-1H-pyrazole-4-carboxylic acids and esters thereof as anticonvulsants, muscle relaxants and anxiolytics
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A novel method of controlling epilepsy, muscle tension, muscular spasticity, and anxiety in living animal bodies by administering compounds of the formula: STR1 wherein: R1 is hydrogen, loweralkyl or a pharmaceutically acceptable cation; R2 and R3, same or different, are hydrogen, loweralkyl, aryl, cycloalkyl, loweralkenyl, 1-adamantyl, heterocyclicaminoalkyl, diloweralkylaminoloweralkyl, or R2 with R3 and adjacent nitrogen may form a heterocyclic ring structure; and the pharmaceutical acceptable acid salts, and tautomeric isomers thereof; and novel pharmaceutical compositions therefor are disclosed.
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- Very Soluble and Photostable Perylene Fluorescent Dyes
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The synthesis of perylene dyes 2 with two terminal alkyl groups is described.Long-chain alkyl groups do not increase, but diminish solubility.Cycloalkyl substituents give a minimum of solubility with medium sized rings and a maximum with the cyclotetradecyl derivative (2p).Very high solubility in organic solvents is attained by substitution with secondary alkyl residues having two long chains.One of them, the dye with the 1-hexylheptyl substituent (2v), exhibits a solubility of more than 100g/l in most solvents, a fluorescent quantum yield of about 100 percent, and a very high photostability, thus making it suitable for special applications.
- Demming, Stefan,Langhals, Heinz
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p. 225 - 230
(2007/10/02)
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