- Direct Access to Primary Amines from Alkenes by Selective Metal-Free Hydroamination
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Direct and selective synthesis of primary amines from easily available precursors is attractive yet challenging. Herein, we report the rapid synthesis of primary amines from alkenes via metal-free regioselective hydroamination at room temperature. Ammonium carbonate was used as ammonia surrogate for the first time, allowing for efficient conversion of terminal and internal alkenes into linear, α-branched, and α-tertiary primary amines under mild conditions. This method provides a straightforward and powerful approach to a wide spectrum of advanced, highly functionalized primary amines which are of particular interest in pharmaceutical chemistry and other areas.
- Du, Yi-Dan,Chen, Bi-Hong,Shu, Wei
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supporting information
p. 9875 - 9880
(2021/03/29)
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- MOF-derived cobalt nanoparticles catalyze a general synthesis of amines
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The development of base metal catalysts for the synthesis of pharmaceutically relevant compounds remains an important goal of chemical research. Here, we report that cobalt nanoparticles encapsulated by a graphitic shell are broadly effective reductive amination catalysts. Their convenient and practical preparation entailed template assembly of cobaltdiamine- dicarboxylic acid metal organic frameworks on carbon and subsequent pyrolysis under inert atmosphere.The resulting stable and reusable catalysts were active for synthesis of primary, secondary, tertiary, and N-methylamines (more than 140 examples).The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, or nitro compounds, and molecular hydrogen under industrially viable and scalable conditions, offering cost-effective access to numerous amines, amino acid derivatives, and more complex drug targets.
- Jagadeesh, Rajenahally V.,Murugesan, Kathiravan,Alshammari, Ahmad S.,Neumann, Helfried,Pohl, Marga-Martina,Radnik, J?rg,Beller, Matthias
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p. 326 - 332
(2017/09/28)
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- Total synthesis of (-)-platensimycin by advancing oxocarbenium- and iminium-mediated catalytic methods
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(-)-Platensimycin is a potent inhibitor of fatty acid synthase that holds promise in the treatment of metabolic disorders (e.g., diabetes and "fatty liver") and pathogenic infections (e.g., those caused by drug-resistant bacteria). Herein, we describe its total synthesis through a four-step preparation of the aromatic amine fragment and an improved stereocontrolled assembly of the ketolide fragment, (-)-platensic acid. Key synthetic advances include 1) a modified Lieben haloform reaction to directly convert an aryl methyl ketone into its methyl ester within 30 seconds, 2) an experimentally improved dialkylation protocol to form platensic acid, 3) a sterically controlled chemo- and diastereoselective organocatalytic conjugate reduction of a spiro-cyclized cyclohexadienone by using the trifluoroacetic acid salt of α-amino di-tert-butyl malonate, 4) a tetrabutylammonium fluoride promoted spiro-alkylative para dearomatization of a free phenol to assemble the cagelike ketolide core with the moderate leaving-group ability of an early tosylate intermediate, and 5) a bismuth(III)-catalyzed Friedel-Crafts cyclization of a free lactol, with LiClO4 as an additive to liberate a more active oxocarbenium perchlorate species and suppress the Lewis basicity of the sulfonyloxy group. The longest linear sequence is 21 steps with an overall yield of 3.8% from commercially available eugenol. Relay tactics: The stereocontrolled assembly of the potent antibiotic (-)-platensimycin in 21 steps and 3.8% yield from eugenol is described (see scheme; TBAF: tetrabutylammonium fluoride; Ts: toluene-4-sulfonyl). Highlights are 1) a rapid oxidative esterification of an acyl aromatic, 2) a reliable dialkylation protocol to form platensic acid, 3) a π-facial conjugate reduction of a dienone, 4) a TBAF-promoted alkylative dearomatization of a free phenol, and 5) a Friedel-Crafts closure of a free lactol.
- Eey, Stanley T.-C.,Lear, Martin J.
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p. 11556 - 11573
(2015/01/16)
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- Dicationic ring-opening reactions of trans -2- phenylcyclopropylamine·HCl: Electrophilic cleavage of the distal (C 2-C3) bond of cyclopropanes
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Electrophilic ring opening of trans-2-phenylcyclopropylamine·HCl occurs at the distal (C2-C3) bond. This is consistent with weakening of the distal bond by the σ-withdrawing ammonium group and charge-charge repulsive effects in the t
- Nilsson Lill, Sten O.,Naredla, Rajasekhar Reddy,Zielinski, Matthew E.,Knoecer, Larecia,Klumpp, Douglas A.
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p. 8922 - 8926
(2013/09/24)
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- Photoinduced Nucleophilic Addition of Ammonia and Alkylamines to Aryl-Substituted Alkenes in the Presence of p-Dicyanobenzene
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The photoamination of 1,1-diphenylpropene (1a) with ammonia and some primary alkylamines in the presence of p-dicyanobenzene gave the corresponding N-substituted 2-amino-1,1-diphenylpropane (2a-e) along with the formation of 3-methyl-4,4-diphenylbutanenitrile (3a), 1,1-diphenylpropane (4a), 3,3-diphenylpropene (5), and diphenylmethane (6).In the case of 1,1-diphenylethene (1b), N-substituted 1-amino-2,2-diphenylethane (2f-h), 4,4-diphenylbutanenitrile (3b), and 1,1-diphenylethane (4b) were produced.In photoamination with t-butylamine in acetonitrile, 3a and 3b were mainly formed as a consequence of the incorporation of acetonitrile to 1a and 1b.The photoamination of 1-phenyl-3,4-dihydronaphthalene (1c) with isopropylamine or t-butylamine gave cis- and trans-N-substituted 1-phenyl-2-amino-1,2,3,4-tetrahydronaphthalenes (15 and 16) in a ratio of ca. 8:2.The mechanism of photoamination is discussed in terms of a photochemical electron transfer of 1 to p-dicyanobenzene followed by a nucleophilic addition of the amine to the cation radical of 1.
- Yamashita, Toshiaki,Shiomori, Koichiro,Yasuda, Masahide,Kensuke, Shima
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p. 366 - 374
(2007/10/02)
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