- Ir-catalyzed chemoselective reduction of β-amido esters: A versatile approach to β-enamino esters
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The conversion of β-amido esters to β-enamino esters is an indispensable step for some synthetic approaches to alkaloids and related medicines. Known methods for such transformation are not only stepwise, but also proceed with low atom-efficiency. Herein, we report a direct and versatile approach that features the Ir-catalyzed chemoselective reduction of β-amido esters with 1,1,3,3-tetramethyldisiloxane (TMDS). In addition, a lack of some signals was observed in the 13C NMR spectra of some alicyclic β-enamino esters. This revealed a longstanding existing but being ignored phenomenon in the literature.
- Yang, Zhi-Ping,Lu, Guang-Sheng,Ye, Jian-Liang,Huang, Pei-Qiang
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p. 1624 - 1631
(2019/01/04)
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- Nickel(II) N-Heterocyclic Carbene Complexes: Versatile Catalysts for C–C, C–S and C–N Coupling Reactions
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A variety of NiII complexes with a wide range of electronic and steric properties, bearing picolylimidazolidene ligands (a–g) and Cp (Cp = η5-C5H5; 2a–f) or Cp* (Cp* = η5-C5Me5; 3a, c, g) groups, have been synthesised and characterised by using NMR spectroscopy and single-crystal X-ray crystallography. The complexes have been used as precatalysts for a wide range of catalytic transformations, which most likely involve a Ni0/NiII catalytic cycle. In particular, the new well-defined 2a, 2c, 3a and 3c complexes have demonstrated great efficiency and versatility towards Suzuki–Miyaura coupling reactions, hydroamination of activated olefins and C–S cross-coupling reactions of aryl halides and thiols under mild conditions.
- Junquera, Lourdes Benítez,Fernández, Francys E.,Puerta, M. Carmen,Valerga, Pedro
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supporting information
p. 2547 - 2556
(2017/05/29)
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- N-Acylaminophenothiazines: Neuroprotective agents displaying multifunctional activities for a potential treatment of Alzheimer's disease
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We have previously reported the multifunctional profile of N-(3-chloro-10H-phenothiazin-10-yl)-3-(dimethylamino)propanamide (1) as an effective neuroprotectant and selective butyrylcholinesterase inhibitor. In this paper, we have developed a series of N-acylaminophenothiazines obtained from our compound library or newly synthesised. At micro- and sub-micromolar concentrations, these compounds selectively inhibited butyrylcholinesterase (BuChE), protected neurons against damage caused by both exogenous and mitochondrial free radicals, showed low toxicity, and could penetrate into the CNS. In addition, N-(3-chloro-10H-phenothiazin-10-yl)-2-(pyrrolidin-1-yl) acetamide (11) modulated the cytosolic calcium concentration and protected human neuroblastoma cells against several toxics, such as calcium overload induced by an l-type Ca2+-channel agonist, tau-hyperphosphorylation induced by okadaic acid and Aβ peptide.
- González-Mu?oz, Gema C.,Arce, Mariana P.,López, Beatriz,Pérez, Concepción,Romero, Alejandro,Barrio, Laura Del,Martín-De-Saavedra, María Dolores,Egea, Javier,León, Rafael,Villarroya, Mercedes,López, Manuela G.,García, Antonio G.,Conde, Santiago,Rodríguez-Franco, María Isabel
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body text
p. 2224 - 2235
(2011/06/22)
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- Bromodimethylsulfonium bromide mediated Michael addition of amines to electron deficient alkenes
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Bromodimethylsulfonium bromide has been found to be an efficient catalyst for the Michael addition of a wide variety of amines to electron deficient alkenes at room temperature. The protocol is very simple and chemoselective. Aliphatic and benzylic amines undergo conjugate addition within a very short period under solvent-free conditions and provide excellent yields of products.
- Khan, Abu T.,Parvin, Tasneem,Gazi, Sarifuddin,Choudhury, Lokman H.
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p. 3805 - 3808
(2008/02/06)
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- Samarium(III) triflate catalyzed conjugate addition of amines to electron-deficient alkenes
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Amines undergo smooth nucleophilic addition to α,β-unsaturated compounds in the presence of a catalytic amount of samarium(III) triflate at ambient temperature to produce the corresponding β-amino compounds in excellent yields. This method is simple, convenient, and works efficiently under mild conditions. Georg Thieme Verlag Stuttgart.
- Yadav,Ramesh Reddy,Gopal Rao,Narsaiah,Subba Reddy
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p. 3447 - 3450
(2008/09/19)
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- Cadmium chloride (CdCl2): An efficient catalyst for conjugate addition of amines to electron-poor alkenes
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Electron-deficient olefins undergo rapid Aza-Michael reaction with a wide range of amines catalyzed by cadmium chloride at room temperature. Copyright Taylor & Francis Group, LLC.
- Vijender, Medamoni,Kishore,Satyanarayana
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p. 591 - 594
(2007/10/03)
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- Zirconium(IV) chloride-mediated chemoselective conjugate addition of aliphatic amines to α,β-ethylenic compounds
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Zirconium chloride efficiently catalyzes the conjugate addition of a variety of aliphatic amines to α,β-unsaturated ester, nitriles, and ketones to give the corresponding β-amino derivatives in excellent yields under mild reaction conditions. Aromatic amines do not participate in this transformation. Copyright Taylor & Francis Group, LLC.
- Meshram,Lakshindra,Reddy,Sadashiv,Yadav
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p. 795 - 801
(2007/10/03)
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- Synthesis of β-amino esters via aza-Michael addition of amines to alkenes promoted on silica: A useful and recyclable surface
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A solvent-free protocol for the synthesis of β-amino esters and nitriles has been developed via conjugate addition of amines to electron-deficient alkenes promoted on silica. The silica surface may be recycled. Both aliphatic and aromatic primary or secondary amines worked efficiently to yield the desired adducts in good to excellent yields.
- Basu, Basudeb,Das, Pralay,Hossain, Ismail
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p. 2630 - 2632
(2007/10/03)
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- Rhodium(II) acetate catalyzed synthesis of cyclic enamides and enamines via β-hydride elimination
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A series of cylic diazoamides and diazoamines were synthesized. Treatment of these cylic diazoamides and diazoamines with a catalytic amount of rhodium(II) acetate furnished the corresponding cyclic enamides and enamines, respectively. Interestingly, cyclic diazoamines produced stereoselectively Z-enamines.
- Muthusamy, Sengodagounder,Gunanathan, Chidambaram,Babu, Srinivasarao Arulananda
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p. 471 - 474
(2007/10/03)
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- CATALYSIS OF THE SPECIFIC MICHAEL ADDITION : THE EXAMPLE OF ACRYLATE ACCEPTORS
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Lewis acids, ferric chloride in particular, catalyze the addition of amine nucleophiles to arcylates.Yields are very good, under mild conditions.Exlusive 1,4-addition occurs, and polymerization is avoided.
- Cabral, Jose,Laszlo, Pierre,Mahe, Loic,Montaufier, Marie-Therese,Randriamahefa, S. Lalatiana
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p. 3969 - 3972
(2007/10/02)
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- Syntheses des alkyl-1 cyclanols fonctionnalises aux positions α, β et γ de la chaine hydrocarbonee
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We have developed a general and versatile synthesis of N,N-dialkylaminoalkyl-, 1-chloroalkyl-, 1-phenoxyalkyl-, 1-thiophenoxyalkyl-, 1-diethoxyalkyl-, and 1-(1,3-dithiolane)alkylcyclanols in good yields by the reaction of α,ω-bis(bromomagnesio)alkanes with the corresponding functionalized carboxylic acid esters.
- Canonne, P.,Belley, M.,Fytas, G.,Plamondon, J.
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p. 168 - 173
(2007/10/02)
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