![2,4-dichloro-7-methylthieno[3,2-d]pyrimidine](http://file1.lookchem.com/cas/reactions/2021/07/14/1074562.svg+xml_ms)
111-68-2Relevant academic research and scientific papers
Oxidation of aldehydes to acyl azides by chromic anhydride-azidotrimethylsilane
Lee,Kwak
, p. 3165 - 3166 (1992)
Aldehydes are efficiently oxidized to acyl azides by azidotrimethylsilane and chromic anhydride at room temperature (aromatic), or at -10°C (aliphatic).
Selective catalytic hydrogenation of nitriles to primary amines using iron pincer complexes
Lange,Elangovan,Cordes,Spannenberg,Jiao,Junge,Bachmann,Scalone,Topf,Junge,Beller
, p. 4768 - 4772 (2016)
The selective catalytic hydrogenation of nitriles to primary amines with the well-defined Fe(PNPCy) pincer complex 2 is reported. This iron pincer catalyst shows superior catalytic activity and selectivity in the reduction of various nitriles including industrially relevant adipodinitrile in high yields under relatively mild conditions.
Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines: Mechanism, scope, and application
Han, Bo,Jiao, Haijun,Wu, Lipeng,Zhang, Jiong
, p. 2059 - 2067 (2021/09/02)
Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective. In this respect, catalytic deoxygenative amide reduction has proven to be promising but challenging, as this approach necessitates selective C–O bond cleavage. Herein, we report the selective hydroboration of primary, secondary, and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst, Zr-H, for accessing diverse amines. Various readily reducible functional groups, such as esters, alkynes, and alkenes, were well tolerated. Furthermore, the methodology was extended to the synthesis of bio- and drug-derived amines. Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C–N bond cleavage-reformation process, followed by C–O bond cleavage.
Selective Room-Temperature Hydrogenation of Amides to Amines and Alcohols Catalyzed by a Ruthenium Pincer Complex and Mechanistic Insight
Ben-David, Yehoshoa,Kar, Sayan,Kumar, Amit,Leitus, Gregory,Milstein, David,Rauch, Michael
, p. 5511 - 5515 (2020/07/21)
We report a room-temperature protocol for the hydrogenation of various amides to produce amines and alcohols. Compared with most previous reports for this transformation, which use high temperatures (typically, 100-200 °C) and H2 pressures (10-100 bar), this system proceeds under extremely mild conditions (RT, 5-10 bar of H2). The hydrogenation is catalyzed by well-defined ruthenium-PNNH pincer complexes (0.5 mol %) with potential dual modes of metal-ligand cooperation. An unusual Ru-amidate complex was formed and crystallographically characterized. Mechanistic investigations indicate that the room-temperature hydrogenation proceeds predominantly via the Ru-N amido/amine metal-ligand cooperation.
Synthesis of oxalamides by acceptorless dehydrogenative coupling of ethylene glycol and amines and the reverse hydrogenation catalyzed by ruthenium
Ben-David, Yehoshoa,Diskin-Posner, Yael,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
, p. 7188 - 7193 (2020/07/23)
A sustainable, new synthesis of oxalamides, by acceptorless dehydrogenative coupling of ethylene glycol with amines, generating H2, homogeneously catalyzed by a ruthenium pincer complex, is presented. The reverse hydrogenation reaction is also accomplished using the same catalyst. A plausible reaction mechanism is proposed based on stoichiometric reactions, NMR studies, X-ray crystallography as well as observation of plausible intermediates.
Facile synthesis of supported Ru-Triphos catalysts for continuous flow application in selective nitrile reduction
Konrath, Robert,Heutz, Frank J.L.,Steinfeldt, Norbert,Rockstroh, Nils,Kamer, Paul C.J.
, p. 8195 - 8201 (2019/09/19)
The selective catalytic hydrogenation of nitriles represents an important but challenging transformation for many homogeneous and heterogeneous catalysts. Herein, we report the efficient and modular solid-phase synthesis of immobilized Triphos-type ligands in very high yields, involving only minimal work-up procedures. The corresponding supported ruthenium-Triphos catalysts are tested in the hydrogenation of various nitriles. Under mild conditions and without the requirement of additives, the tunable supported catalyst library provides selective access to both primary amines and secondary imines. Moreover, the first application of a Triphos-type catalyst in a continuous flow process is presented demonstrating high catalyst life-time over at least 195 hours without significant activity loss.
Selective Hydrogenation of Nitriles to Primary Amines by using a Cobalt Phosphine Catalyst
Adam, Rosa,Bheeter, Charles Beromeo,Cabrero-Antonino, Jose R.,Junge, Kathrin,Jackstell, Ralf,Beller, Matthias
, p. 842 - 846 (2017/03/17)
A general procedure for the catalytic hydrogenation of nitriles to primary amines by using a non-noble metal-based system is presented. Co(acac)3 in combination with tris[2-(dicyclohexylphosphino)ethyl]phosphine efficiently catalyzes the selective hydrogenation of a wide range of (hetero)aromatic and aliphatic nitriles to give the corresponding amines.
A method of synthesizing all hair (by machine translation)
-
Paragraph 0036; 0038; 0039; 0042, (2018/03/01)
The invention relates to a method of synthesizing all hair, which belongs to the technical field of organic synthesis. In order to market and common enanthaldehyde preparation on raw materials (enanthaldehyde preparation is castor oil cracking by-product, source sufficient), and hydroxylamine reaction generating aldoxime, aldoxime further dehydration to obtain age nitrile, the age nitrile passes through hydrogenation to obtain the hair loss. In accordance with the invention described from the enanthaldehyde preparation process to age nitrile reaction process has the advantages of simple and convenient operation, mild condition, material consumption and energy consumption and the like, and more in line with the concept of green chemical industry; the invention prepared by the hair loss not only content is high, and the quality is good, selective stability. (by machine translation)
An improved and one-pot procedure to the synthesis of symmetric amines by domino reactions of 5-methyl-1,3,4-thiadiazole-2-amine, a new nitrogen atom donor, and alkyl halides
Soleiman-Beigi, Mohammad,Mohammadi, Fariba
, p. 2123 - 2128 (2017/10/26)
Abstract: A new one-pot method has been introduced in this work for the synthesis of symmetrical primary, secondary, and tertiary alkyl amines from alkyl halides and 5-methyl-1,3,4-thiadiazole-2-amine as a nitrogen-transfer reagent. In this method, all three types of amines have been successfully prepared after changing the ratio of substrates and base control. In addition to the introduction of a new nitrogen-transfer reagent, other important features of this work include normal atmospheric conditions and excellent yields under mild reaction conditions.
Photometric Characterization of the Reductive Amination Scope of the Imine Reductases from Streptomyces tsukubaensis and Streptomyces ipomoeae
Matzel, Philipp,Krautschick, Lukas,H?hne, Matthias
, p. 2022 - 2027 (2017/10/07)
Imine reductases (IREDs) have emerged as promising enzymes for the asymmetric synthesis of secondary and tertiary amines starting from carbonyl substrates. Screening the substrate specificity of the reductive amination reaction is usually performed by time-consuming GC analytics. We found two highly active IREDs in our enzyme collection, IR-20 from Streptomyces tsukubaensis and IR-Sip from Streptomyces ipomoeae, that allowed a comprehensive substrate screening with a photometric NADPH assay. We screened 39 carbonyl substrates combined with 17 amines as nucleophiles. Activity data from 663 combinations provided a clear picture about substrate specificity and capabilities in the reductive amination of these enzymes. Besides aliphatic aldehydes, the IREDs accepted various cyclic (C4–C8) and acyclic ketones, preferentially with methylamine. IR-Sip also accepted a range of primary and secondary amines as nucleophiles. In biocatalytic reactions, IR-Sip converted (R)-3-methylcyclohexanone with dimethylamine or pyrrolidine with high diastereoselectivity (>94–96 % de). The nucleophile acceptor spectrum depended on the carbonyl substrate employed. The conversion of well-accepted substrates could also be detected if crude lysates were employed as the enzyme source.
