30551-89-4Relevant articles and documents
Parahydrogen-Induced Polarization Relayed via Proton Exchange
Them, Kolja,Ellermann, Frowin,Pravdivtsev, Andrey N.,Salnikov, Oleg G.,Skovpin, Ivan V.,Koptyug, Igor V.,Herges, Rainer,H?vener, Jan-Bernd
supporting information, p. 13694 - 13700 (2021/09/07)
The hyperpolarization of nuclear spins is a game-changing technology that enables hitherto inaccessible applications for magnetic resonance in chemistry and biomedicine. Despite significant advances and discoveries in the past, however, the quest to establish efficient and effective hyperpolarization methods continues. Here, we describe a new method that combines the advantages of direct parahydrogenation, high polarization (P), fast reaction, and low cost with the broad applicability of polarization transfer via proton exchange. We identified the system propargyl alcohol + pH2 → allyl alcohol to yield 1H polarization in excess of P ≈ 13% by using only 50% enriched pH2 at a pressure of ≈1 bar. The polarization was then successfully relayed via proton exchange from allyl alcohol to various target molecules. The polarizations of water and alcohols (as target molecules) approached P ≈ 1% even at high molar concentrations of 100 mM. Lactate, glucose, and pyruvic acid were also polarized, but to a lesser extent. Several potential improvements of the methodology are discussed. Thus, the parahydrogen-induced hyperpolarization relayed via proton exchange (PHIP-X) is a promising approach to polarize numerous molecules which participate in proton exchange and support new applications for magnetic resonance.
METHOD FOR PRODUCING PRIMARY AMINES
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Paragraph 0047; 0050, (2019/08/27)
PROBLEM TO BE SOLVED: To provide a method for producing primary amines industrially, economically, safely, and efficiently. SOLUTION: Provided is a method for producing primary amines represented by R1-NH2 by reacting, in the presence of an acid catalyst, an imine compound, represented by formula (1), and an alcohol represented by R4-(OH)n, comprising a step of distilling off the primary amine from a reaction mixture which is in the reaction process. (R1 is an alkyl group or an alkenyl group; R2 is H, an alkyl group, or an aryl group; R3 is an aryl group; R4 is an n-valent hydrocarbon roup; and n is an integer of 1 to 3.) SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
An amine protecting group deprotectable under nearly neutral oxidative conditions
Shahsavari, Shahien,McNamara, Chase,Sylvester, Mark,Bromley, Emily,Joslin, Savannah,Lu, Bao-Yuan,Fang, Shiyue
, p. 1750 - 1757 (2018/08/21)
The 1,3-dithiane-based dM-Dmoc group was studied for the protection of amino groups. Protection was achieved under mild conditions for aliphatic amines, and under highly reactive conditions for the less reactive arylamines. Moderate to excellent yields were obtained. Deprotection was performed by oxidation followed by treating with a weak base. The yields were good to excellent. The new amino protecting group offers a different dimension of orthogonality in reference to the commonly used amino protecting groups in terms of deprotection conditions. It is expected to allow a collection of transformations to be carried out on the protected substrates that are unattainable using any known protecting groups.
Spectroscopic Evidence for Aminomethylene (H?C??NH2)—The Simplest Amino Carbene
Eckhardt, André K.,Schreiner, Peter R.
supporting information, p. 5248 - 5252 (2018/03/21)
Although N-heterocyclic carbenes have been well-studied, the simplest aminocarbene, aminomethylene H?C??NH2, has not been spectroscopically identified to date. Herein we report the gas-phase preparation of aminomethylene by high-vacuum flash py
Accessing Frustrated Lewis Pair Chemistry through Robust Gold@N-Doped Carbon for Selective Hydrogenation of Alkynes
Fiorio, Jhonatan Luiz,Gon?alves, Renato Vitalino,Teixeira-Neto, Erico,Ortu?o, Manuel A.,López, Núria,Rossi, Liane Marcia
, p. 3516 - 3524 (2018/04/14)
Pyrolysis of Au(OAc)3 in the presence of 1,10-phenanthroline over TiO2 furnishes a highly active and selective Au nanoparticle (NP) catalyst embedded in a nitrogen-doped carbon support, Au@N-doped carbon/TiO2 catalyst. Parameters such as pyrolysis temperature, type of support, and nitrogen ligands as well as Au/ligand molar ratios were systematically investigated. Highly selective hydrogenation of numerous structurally diverse alkynes proceeded in moderate to excellent yield under mild conditions. The high selectivity toward the industrially important alkene substrates, functional group tolerance, and the high recyclability makes the catalytic system unique. Both high activity and selectivity are correlated with a frustrated Lewis pairs interface formed by the combination of gold and nitrogen atoms of N-doped carbon that, according to density functional theory calculations, can serve as a basic site to promote the heterolytic activation of H2 under very mild conditions. This "fully heterogeneous" and recyclable gold catalyst makes the selective hydrogenation process environmentally and economically attractive.
Preparation method of allyl amine mixture
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Paragraph 0013; 0014; 0015; 0016; 0017, (2017/04/27)
The invention discloses a preparation method of an allyl amine mixture. The preparation method includes following steps: S1, pouring a catalyst into a reation kettle, adding a certain amount of ammonium hydroxide, rising temperature, and adding chloropropene for ammonolysis reaction; S2, holding the temperature of the step 1, and adding liquid caustic soda; S3, rectifying a reaction product to evaporate water and excessive ammonia; S4, at corresponding temperature, collecting fraction-monoallyl amine; S, at corresponding temperature, collecting fraction-diallyl amine; S6, at corresponding temperature, collecting fraction-trially amine; S7, adding caustic soda flakes into a collected fraction mixture, and performing liquid separation to obtain. The preparation method is mild in reaction condition, ammonium hydroxide is used to replace ammonia in existing methods, and complex ventilation equipment is not needed, so that production cost is saved; by adding the caustic soda flakes, water absorbing effect can be realized, purity of the allyl amine mixture prepared by the method can be effectively improved, and the preparation method is simple to operate, high in yield and worthy of popularization.
METHOD FOR THE IMMOBILIZATION OF BIOMOLECULES
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, (2017/09/08)
The invention relates to a method for the immobilization of biomolecules containing at least one sulfhydryl group, which method comprises contacting a modified metal surface with the biomolecule irradiating the resulting surface with UV radiation in the presence of a photo-initiator, wherein said metal surface is modified with a cross-linker compound comprising a terminal thiol or dithiol group covalently linked to the metal surface, a spacer group, which at the other terminal end is carrying an isolated double or triple bond.
O -Phthalaldehyde catalyzed hydrolysis of organophosphinic amides and other P(O)-NH containing compounds
Li, Bin-Jie,Simard, Ryan D.,Beauchemin, André M.
supporting information, p. 8667 - 8670 (2017/08/10)
Over 50 years ago, Jencks and Gilchrist showed that formaldehyde catalyses the hydrolysis of phosphoramidate through electrophilic activation, induced by covalent attachment to its nitrogen atom. Given our interest in the use of aldehydes as catalysts, this work was revisited to identify a superior catalyst, o-phthalaldehyde, which facilitates hydrolyses of various organophosphorus compounds bearing P(O)-NH subunits under mild conditions. Interestingly, chemoselective hydrolysis of the P(O)-N bonds could be accomplished in the presence of P(O)-OR bonds.
A metagenomics approach for new biocatalyst discovery: Application to transaminases and the synthesis of allylic amines
Baud, Damien,Jeffries, Jack W. E.,Moody, Thomas S.,Ward, John M.,Hailes, Helen C.
, p. 1134 - 1143 (2017/08/14)
Transaminase enzymes have significant potential for the sustainable synthesis of amines using mild aqueous reaction conditions. Here a metagenomics mining strategy has been used for new transaminase enzyme discovery. Starting from oral cavity microbiome samples, DNA sequencing and bioinformatics analyses were performed. Subsequent in silico mining of a library of contiguous reads built from the sequencing data identified 11 putative Class III transaminases which were cloned and overexpressed. Several screening protocols were used and three enzymes selected of interest due to activities towards substrates covering a wide structural diversity. Transamination of functionalized cinnamaldehydes was then investigated for the production of valuable amine building blocks.
Gold-Ligand-Catalyzed Selective Hydrogenation of Alkynes into cis-Alkenes via H2 Heterolytic Activation by Frustrated Lewis Pairs
Fiorio, Jhonatan L.,López, Núria,Rossi, Liane M.
, p. 2973 - 2980 (2017/05/31)
The selective hydrogenation of alkynes to alkenes is an important synthetic process in the chemical industry. It is commonly accomplished using palladium catalysts that contain surface modifiers, such as lead and silver. Here we report that the adsorption of nitrogen-containing bases on gold nanoparticles results in a frustrated Lewis pair interface that activates H2 heterolytically, allowing an unexpectedly high hydrogenation activity. The so-formed tight-ion pair can be selectively transferred to an alkyne, leading to a cis isomer; this behavior is controlled by electrostatic interactions. Activity correlates with H2 dissociation energy, which depends on the basicity of the ligand and its reorganization on activation of hydrogen. High surface occupation and strong Au atom-ligand interactions might affect the accessibility and stability of the active site, making the activity prediction a multiparameter function. The promotional effect found for nitrogen-containing bases with two heteroatoms was mechanistically described as a strategy to boost gold activity. (Graph Presented).
