- Cobalt-catalyzed carbonylative copolymerization of N-alkylazetidines and tetrahydrofuran
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(Chemical Equation Presented) A living polymerization: Poly(amide-coester)s with either gradient or segmental ester distribution are formed by the cobalt-catalyzed polymerization of azetidine in THF in the absence or presence of Lil, respectively. Periodic addition of azetidine results in copolymers with multiple amide blocks separated by ester segments (see picture). The polymers undergo a two-stage chemical degradation.
- Liu, Guosheng,Jia, Li
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Read Online
- Bio-based N-alkyl-2-pyrrolidones by Pd-catalyzed reductive N-alkylation and decarboxylation of glutamic acid
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Environmental regulations boost the search for new safer and less toxic bio-based solvents to replace controversial high-boiling solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide in the chemical industry. Recently, N-alkyl-2-pyrrolidones and 5-methyl-N-alkyl-2-pyrrolidones were proposed as attractive alternative solvents for many applications. Here, we report a bio-based two-step chemocatalytic system for the synthesis of a broad range of N-alkyl-2-pyrrolidones starting from glutamic acid and C3-C5 carbonyl compounds. In the first step N-mono-alkylated derivatives of glutamic acid were synthesized in high yields (>85%) by a mild and efficient Pd-catalyzed reductive N-alkylation. Subsequently, thermally induced lactamization to the corresponding N-alkylpyroglutamic acid followed by Pd-catalyzed decarboxylation at 250 °C under inert atmosphere resulted in N-alkyl-2-pyrrolidones. Hydrolytic degradation was partially counteracted by the neutralization of the N-alkylpyroglutamic acid substrate with a base, resulting in yields up to 82%. Finally, both reaction steps were successfully combined in a one-pot process using the same Pd/Al2O3 catalyst in different conditions of gas atmosphere and temperature.
- De Schouwer, Free,Adriaansen, Sander,Claes, Laurens,De Vos, Dirk E.
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p. 4919 - 4929
(2017/10/19)
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- Organocatalytic diimide reduction of enamides in water
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Bridged flavinium organocatalysts have displayed efficacy in the diimide mediated reduction of enamides in aqueous conditions. This represents the first diimide reduction of an electron rich alkene and offers a clean alternative to the use of alkylating agents for N-alkylation.
- Marsh, Barrie J.,Heath, Emma L.,Carbery, David R.
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supporting information; experimental part
p. 280 - 282
(2011/02/23)
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- Synthesis of biobased N-methylpyrrolidone by one-pot cyclization and methylation of γ-aminobutyric acid
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N-Methylpyrrolidone (NMP) is an industrial solvent that is currently based on fossil resources. In order to prepare it in a biobased way, the possibility to synthesize NMP from γ-aminobutyric acid (GABA) was investigated, since GABA can be obtained from glutamic acid, an amino acid that is present in many plant proteins. Cyclization of GABA to 2-pyrrolidone and subsequent methylation of 2-pyrrolidone to NMP was achieved in a one-pot procedure, using methanol as the methylating agent and a halogen salt (i.e. ammonium bromide) as a catalyst. A selectivity above 90% was achieved, as well as a high conversion. Methylation of 2-pyrrolidone could also be done with dimethyl carbonate, but then the selectivity for NMP was less (67%).
- Lammens, Tijs M.,Franssen, Maurice C. R.,Scott, Elinor L.,Sanders, Johan P. M.
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scheme or table
p. 1430 - 1436
(2010/09/05)
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- Triton B-mediated mild, convenient, and efficient method for the selective alkylation of cyclic secondary amines and thiols
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Alkylation of cyclic secondary amines, thiols, and pyridazinones has been demonstrated with alkyl halides using Triton B as base and reaction medium.
- Meshram,Reddy, B. Chennakesava,Goud, P. Ramesh
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experimental part
p. 2297 - 2303
(2009/12/01)
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- Synthesis, conformational characteristics and anti-influenza virus A activity of some 2-adamantylsubstituted azacycles
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The broad-spectrum antiviral activity of 2-(2-adamantyl)piperidines 11, 13a,b, and 15, 3-(2-adamantyl)pyrrolidines 27, 21a-g and 2-(2-adamantylmethyl)piperidines 30, 32a-c, and 35a-d was examined. Several compounds in the new series were potent against influenza A H3N2 virus. When 1-aminoethyl pharmacophore group of 2-rimantadine 4 (2-isomer of rimantadine) is included into a saturated nitrogen heterocycle, see compound 11, potency was retained. The diamine derivatives 21e-g and particularly 35a-c possessing three pharmocophoric groups, that is, the adamantyl and the two amine groups, exhibited high potency. The new compounds did not afford specific activity at non-toxic concentrations against any of the other viruses tested. According to NMR spectroscopy and molecular mechanics calculations it is striking that the parent structures 11 and 27 adopt a fixed trans conformation around C2{single bond}C2′ bond. In the parent amines, which proved to be active compounds, the distance between nitrogen and adamantyl pharmacophoric groups was different; N{single bond}C2′ distance is 3.7, 3.8 A for 27, 30 and 2.5 A for 11 suggesting that M2 receptor site can accommodate different in size and orientation lipophilic cages.
- Setaki, Despina,Tataridis, Dimitris,Stamatiou, George,Kolocouris, Antonios,Foscolos, George B.,Fytas, George,Kolocouris, Nicolas,Padalko, Elizaveta,Neyts, Johan,Clercq, Erik De
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p. 248 - 273
(2008/02/07)
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- Novel 3-(2-adamantyl)pyrrolidines with potent activity against influenza A virus - Identification of aminoadamantane derivatives bearing two pharmacophoric amine groups
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The 3-(2-adamantyl)pyrrolidines 8a-g, 14 were synthesized and evaluated for activity against influenza A virus. The parent N-H compound 14 was several times more active than amantadine against H2N2 and H3N2 influenza A virus. The combined use of NMR spectroscopy and computational chemistry showed that the conformation around the pyrrolidine-adamantyl carbon-carbon bond is trans and the pyrrolidine heterocycle has an envelope conformation with C-2 out of the plane of the other ring atoms. N-Dialkylaminoethyl substitution of compound 14 resulted in the potent diamine analogues 8e,f,g. Interestingly, their lactam amine precursors were also active. Compounds 8e,f,g are the first adamantane derivatives, bearing two amine groups, reported to be active against influenza A virus.
- Stamatiou, George,Kolocouris, Antonios,Kolocouris, Nicolas,Fytas, George,Foscolos, George B,Neyts, Johan,De Clercq, Erik
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p. 2137 - 2142
(2007/10/03)
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- Reductive O- and N-alkylations. Alternative catalytic methods to nucleophilic substitution
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Different amides have been selectively mono-N-alkylated using catalytic heterogeneous palladium and carbonyl compounds as alkylating agents. The same salt free method has been applied to the synthesis of ethers from alcohols. Reaction parameters have been studied in detail and a mechanism is proposed.
- Fache, Fabienne,Bethmont, Valerie,Jacquot, Laurent,Lemaire, Marc
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p. 231 - 238
(2007/10/03)
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- Extension of the Eschweiler-Clarke procedure to the N-alkylation of amides
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The selective N-alkylation of amides (cyclic or acyclic) under hydrogen is reported using aldehydes or ketones as alkylating agents and Pd/C/Na2SO4 as catalyst. Good isolated yields are obtained (81% to 98%).
- Fache, Fabienne,Jacquot, Laurent,Lemaire, Marc
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p. 3313 - 3314
(2007/10/02)
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- Synthesis of Pyrrolidines and Pyrrolidinones by the Rhodium Complex Catalyzed Cyclization of Unsaturated Amines
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N-Allylic arylamines react with carbon monoxide, sodium borohydride, 2-propanol, and catalytic amounts of the zwitterionic complex η6-C6H6BPh3-Rh(COD)+ (1), to form pyrrolidines as the main products in most cases.Pyrrolidinones result from N-allylic alkylamines.An alternate route to the lactams from N-allylic alkylamines involves synthesis gas instead of CO/NaBH4, together with the dual catalytic system 1/2.Complementary to the N-allylic arylamine route to pyrrolidines with NaBH4 and 1 is the use of synthesis gas, 1, and 1,4-bis(diphenylphosphino)butane.
- Zhou, Jian-Qiang,Alper, Howard
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p. 3328 - 3331
(2007/10/02)
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- EFFICIENT SYNTHESIS OF N-SUBSTITUTED LACTAMS FROM (N-ARYLSULFONYLOXY)AMINES AND CYCLIC KETONES
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A new method is reported for the direct preparation of N-substituted lactams from cycloalkanones.N-(p-nitrobenzenesulfonoxyl) methylamine 1a (CH3NH-OSO2C6H4NO2) was reacted with a series of cycloalkanones to give good yields of N-methyl lactams.An addition-rearrangement pathway accounts for the ring-expanded lactam products.A series of N-alkyl-N-arylsulfonoxyl amines were generated in situ and reacted with cyclobutanone to give N-alkyl pyrrolidinones in high yields.
- Hoffman, Robert V.,Salvador, James M.
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p. 4207 - 4210
(2007/10/02)
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- ELECTROREDUCTIVE N-ALKYLATION OF AMIDES, CARBAMATES, AND N-HETEROCYCLES
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The N-alkylation of amides, lactams, carbamates, and N-heterocycles was easily attained in good yields by the electroreduction of the substrates in the presence of alkyl halides.
- Shono, Tatsuya,Kashimura, Shigenori,Nogusa, Hideo
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p. 425 - 428
(2007/10/02)
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