- N -Acyliminium Ion Chemistry: Improving the Access to Unsaturated γ-Lactams and Their N -α-Methoxylated Derivatives: Application to an Expeditive Synthesis of (±)-Crispine A
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An improved synthesis of unsaturated γ-lactams by condensation of various primary amines with 2,5-dimethoxy-2,5-dihydrofuran is described. A modified mechanism for this reaction is suggested. Synthesis of their N -α-methoxylated derivatives, as N -acyliminium ion precursors, is also reported. Finally, a short synthesis of (±)-crispine A is presented as an illustrative application.
- Drici, Wassila,Fayssal, Sandra Abi,Lazouni, Imane,Pérard-Viret, Jo?lle,Souquet, Florence,Thueillon, Sébastien
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p. 2970 - 2978
(2020/10/18)
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- Unprecedented selective homogeneous cobalt-catalysed reductive alkoxylation of cyclic imides under mild conditions
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The first general and efficient non-noble metal-catalysed reductive C2-alkoxylation of cyclic imides (phthalimides and succinimides) is presented. Crucial for the success is the use of [Co(BF4)2·6H2O/triphos (L1)] combination and no external additives are required. Using the optimal cobalt-system, the hydrogenation of the aromatic ring of the parent phthalimide is avoided and only one of the carbonyl groups is selectively functionalized. The resulting products, N- and aryl-ring substituted 3-alkoxy-2,3-dihydro-1H-isoindolin-1-one and N-substituted 3-alkoxy-pyrrolidin-2-one derivatives, are prepared under mild conditions in good to excellent isolated yields. Intramolecular reductive couplings can also be performed affording tricyclic compounds in a one-step process. The present protocol opens the way to the development of new base-metal processes for the straightforward synthesis of functionalized N-heterocyclic compounds of pharmaceutical and biological interest.
- Cabrero-Antonino, Jose R.,Adam, Rosa,Papa, Veronica,Holsten, Mattes,Junge, Kathrin,Beller, Matthias
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p. 5536 - 5546
(2017/08/01)
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- Selective Ruthenium-Catalyzed Reductive Alkoxylation and Amination of Cyclic Imides
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Reported herein, for the first time, is the selective ruthenium-catalyzed reductive alkoxylation and amination of phthalimides/succinimides. Notably, this novel methodology avoids hydrogenation of the aromatic ring and allows methoxylation of substituted imides with good to excellent selectivity for one of the carbonyl groups. The reported method opens the door to the development of new processes for the selective synthesis of various functionalized N-heterocyclic compounds. As an example, intramolecular reductive couplings to afford tricyclic compounds are presented for the first time.
- Cabrero-Antonino, Jose R.,Sorribes, Ivn,Junge, Kathrin,Beller, Matthias
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supporting information
p. 387 - 391
(2016/01/25)
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- Novel synthesis of 2-aminopentanedinitriles from 2-(bromomethyl)aziridines and their transformation into 2-imino-5-methoxypyrrolidines and 5-methoxypyrrolidin-2-ones
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1-Arylmethyl-2-(bromomethyl)aziridines were transformed into 2-[N-(arylmethyl)amino]pentanedinitriles upon treatment with an excess of potassium cyanide in DMSO through an unprecedented and peculiar reaction mechanism, involving base-induced ring opening
- D'hooghe, Matthias,Van Nieuwenhove, Andries,Van Brabandt, Willem,Rottiers, Mario,De Kimpe, Norbert
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p. 1064 - 1070
(2008/09/17)
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- Amnesia-reversal activity of a series of 5-alkoxy-1-arylcarbonyl-2-pyrrolidinones and 5-alkoxy-1-arylmethyl-2-pyrrolidinones
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A series of 5-alkoxy-1-arylcarbonyl-2-pyrrolidinones (1-27) were prepared by condensation of arylcarbonyl chlorides with 5-alkoxy-2-pyrrolidinones in the presence of butyl lithium in tetrahydrofuran.Alkylation of these intermediates with substituted benzy
- Toja, E,Gorini, C,Zirotti, C,Barzaghi, F,Galliani, G
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p. 415 - 422
(2007/10/02)
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- INTRAMOLECULAR REACTIONS OF-PROPYNYLSILANES WITH N-ACYLIMINIUM; CUPRATES SN2' REACTIONS OF THE ALLENIC PRODUCTS AS A ROUTE TO TRANS-FUSED CARBOBICYCLES
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Intramolecular acid-assisted reactions of 2-propynylsilanes with cyclic N-acyliminium ion precursors lead to bridged azabicyclic systems 34-45 (Table I), containing the uncommon α-allenic amide funcionality.After introduction of a tert-butoxycarbonyl or a
- Klaver, Wim J.,Moolenaar, Marinus J.,Hiemstra, Henk,Speckamp, W. Nico
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p. 3805 - 3818
(2007/10/02)
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- ω-Alkoxy Lactams as Dipolar Synthons. Silicon-Assisted Synthesis of Azabicycles and a γ-Amino Acid
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Alkylation of the lithium enolates derived from ω-alkoxy lactams 1a-c with unsaturated iodides 4 affords 5 in high yields (Table I).Those alkylation products 5, which contain an allyl- or propargylsilane moiety, undergo cyclization on acid treatment to fu
- Hiemstra, Henk,Klaver, Wim J.,Speckamp, W. Nico
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p. 1149 - 1151
(2007/10/02)
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