- Electrochemical Amide Bond Formation from Benzaldehydes and Amines: Oxidation by Cathodic-Generated Hydrogen Peroxide
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Although amide bond formation from aldehydes and amines is a popular synthetic tool, most of the previously reported reactions depend on transition-metal catalysts or expensive oxidants. We considered that a more environmentally benign and safer approach could be achieved by electrochemistry. Nineteen benzamide derivatives were obtained with this reaction. NMR studies, cyclic voltammetry (CV) investigations, and control experiments showed that the corresponding intermediate, a hemiaminal, was transformed into the amide by oxidation with hydrogen peroxide generated in situ by cathodic reduction of molecular oxygen.
- Kurose, Yuma,Imada, Yasushi,Okada, Yohei,Chiba, Kazuhiro
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supporting information
p. 3844 - 3846
(2020/06/23)
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- Chemoselective amide reductions by heteroleptic fluoroaryl boron Lewis acids
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The heteroleptic borane catalyst (C6F5)2B(CH2CH2CH2)BPin is found to hydrosilylatively reduce amides under mild conditions. Simple tertiary amides can be reduced using Me2EtSiH, whereas tertiary benzamides required a more reactive secondary silane, Et2SiH2, for efficient reduction. The catalytic system described exhibits exceptional chemoselectivity in the reduction of oligoamides and tolerates functionalities which are prone to reduction under similar conditions.
- Peruzzi, Michael T.,Mei, Qiong Qiong,Lee, Stephen J.,Gagné, Michel R.
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supporting information
p. 5855 - 5858
(2018/06/13)
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- A Manganese Pre-Catalyst: Mild Reduction of Amides, Ketones, Aldehydes, and Esters
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A new (N-phosphinoamidinate)manganese complex is shown to be a useful pre-catalyst for the hydrosilative reduction of carbonyl compounds, and in most cases at room temperature. The Mn-catalyzed reduction of tertiary amides to tertiary amines, with a useful scope, is demonstrated for the first time by use of this catalyst, and is competitive with the most effective transition-metal catalysts known for such transformations. Ketones, aldehydes, and esters were also successfully reduced under mild conditions by using this new Mn catalyst.
- Kelly, Colin M.,McDonald, Robert,Sydora, Orson L.,Stradiotto, Mark,Turculet, Laura
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supporting information
p. 15901 - 15904
(2017/12/13)
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- Efficient modulation of γ-aminobutyric acid type a receptors by piperine derivatives
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Piperine activates TRPV1 (transient receptor potential vanilloid type 1 receptor) receptors and modulates γ-aminobutyric acid type A receptors (GABAAR). We have synthesized a library of 76 piperine analogues and analyzed their effects on GABAAR by means of a two-microelectrode voltage-clamp technique. GABAAR were expressed in Xenopus laevis oocytes. Structure-activity relationships (SARs) were established to identify structural elements essential for efficiency and potency. Efficiency of piperine derivatives was significantly increased by exchanging the piperidine moiety with either N,N-dipropyl, N,N-diisopropyl, N,N-dibutyl, p-methylpiperidine, or N,N-bis(trifluoroethyl) groups. Potency was enhanced by replacing the piperidine moiety by N,N-dibutyl, N,N-diisobutyl, or N,N-bistrifluoroethyl groups. Linker modifications did not substantially enhance the effect on GABAAR. Compound 23 [(2E,4E)-5-(1,3-benzodioxol-5-yl)-N,N-dipropyl-2,4-pentadienamide] induced the strongest modulation of GABAA (maximal GABA-induced chloride current modulation (IGABA-max = 1673% ± 146%, EC 50 = 51.7 ± 9.5 μM), while 25 [(2E,4E)-5-(1,3-benzodioxol- 5-yl)-N,N-dibutyl-2,4-pentadienamide] displayed the highest potency (EC 50 = 13.8 ± 1.8 μM, IGABA-max = 760% ± 47%). Compound 23 induced significantly stronger anxiolysis in mice than piperine and thus may serve as a starting point for developing novel GABA AR modulators.
- Sch?ffmann, Angela,Wimmer, Laurin,Goldmann, Daria,Khom, Sophia,Hintersteiner, Juliane,Baburin, Igor,Schwarz, Thomas,Hintersteininger, Michael,Pakfeifer, Peter,Oufir, Mouhssin,Hamburger, Matthias,Erker, Thomas,Ecker, Gerhard F.,Mihovilovic, Marko D.,Hering, Steffen
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supporting information
p. 5602 - 5619
(2014/08/05)
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- Synthesis of 1-aminoisoquinolines by gold(III)-mediated domino reactions from 2-alkynylbenzamides and ammonium acetate
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A facile synthetic route toward pharmaceutically interesting 1-aminoisoquinoline derivatives by gold(III)-mediated domino reactions is described. This synthetic protocol starts from readily available 2-alkynylbenzamides and ammonium acetate and takes plac
- Long, Yuhua,She, Zhigang,Liu, Xiaochen,Chen, Yu
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p. 2579 - 2588
(2013/04/24)
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- Hydrogen peroxide mediated efficient amidation and esterification of aldehydes: Scope and selectivity
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An efficient method for the amidation and esterification of aldehydes utilizing hydrogen peroxide as an oxidant has been developed. Cyclic amines and primary alcohols selectively reacted with aromatic aldehydes under mild conditions to yield the corresponding amides and esters.
- Tank, Rekha,Pathak, Uma,Vimal, Manorama,Bhattacharyya, Shubhankar,Pandey, Lokesh Kumar
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supporting information; experimental part
p. 3350 - 3354
(2012/01/06)
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