68471-58-9Relevant articles and documents
A lactam-derived vinyl boronate as a stable and crystalline reagent for the synthesis of 2-substituted piperidines by Pd-catalyzed coupling reactions
Ferrali, Alessandro,Guarna, Antonio,Lo Galbo, Fabrizio,Occhiato, Ernesto G.
, p. 5271 - 5274 (2004)
A δ-valerolactam-derived vinyl triflate has been converted into the corresponding vinyl boronate by Pd-catalyzed coupling with bis(pinacolato) diboron, which results in an umpolung. This boronate efficiently couples under Pd catalysis with aryl and hetero
β-Functionalization of Saturated Aza-Heterocycles Enabled by Organic Photoredox Catalysis
Holmberg-Douglas, Natalie,Choi, Younggi,Aquila, Brian,Huynh, Hoan,Nicewicz, David A.
, p. 3153 - 3158 (2021/04/06)
The direct β-functionalization of saturated aza-heterocycles has remained a synthetic challenge because of the remote and unactivated nature of β-C-H bonds in these motifs. Herein, we demonstrate the β-functionalization of saturated aza-heterocycles enabl
Synthesis and Structural Elucidation of 1,2-Disubstituted 3-Fluoropiperidines
Evans, Paul,Fischer, Pauline,Müller-Bunz, Helge,Morris, Morgan
, (2020/02/28)
The work described details the reaction between Selectfluor and a series of 1-carbonyloxy and 1-sulfonyl 2-piperidines in order to generate 3-fluoro-2-methoxypiperidines 3a–f. Their subsequent reaction with allyltrimethylsilane, in the presence of BF3 and TiCl4, is then reported. Studies involving a combination of single-crystal X-ray crystallography and NMR spectroscopy indicate that the allylation process is cis-selective for both carbamate and sulfonamide variants and that optimal levels of diastereoselectivity are obtained using the N-2-nitrobenzene sulfonyl (2-Ns) group. In this manner, the synthesis of a series of 2-allyl 3-fluoro-substituted piperidines (5a, c–f) was achieved. The conversion of both the cis and trans-N-tosyl adducts (5d) into 3-fluorinated analogues of the natural products pelletierine (10) and coniine (11) is subsequently detailed.
Fragment-oriented synthesis: β-elaboration of cyclic amine fragments using enecarbamates as platform intermediates
Trindade, Alexandre F.,Faulkner, Emily L.,Leach, Andrew G.,Nelson, Adam,Marsden, Stephen P.
, p. 8802 - 8805 (2020/08/17)
A strategy for the β-sp3 functionalisation of cyclic amines is described. Regioselective conversion of protected amines to enecarbamates is achieved through electrochemical oxidation; these intermediates can be derivatised by functionalised alkyl halides under photoredox catalysis. The potential of the methods is highlighted by direct growth of a DCP2B-binding fragment. This journal is
A process for the preparation and synthetic ChondriamideA and ChondriamideC method (by machine translation)
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Paragraph 0093-0097; 0129-0132, (2018/09/13)
The invention provides a process for the preparation of synthetic Chondriamide A and Chondriamide C and method, wherein the invention provides a process for the preparation, including: formula (I) compounds of structure, palladium catalyst, phosphorus ligand, alkali and organic solvent at room temperature the illumination reaction, formula (II) structure obtained olefin; wherein through the selection of a particular phosphorus ligand; make the method of the invention can be under the photocatalysis, room temperature to realize high-efficient catalytic conversion, and the mild reaction conditions, simple operation, in line with the development of green environment-friendly chemical requirements, and the range of choice of substrate and functional group compatibility has more universal, and has outstanding chemical selectivity; and the method can be successfully applied to complex molecular introducing carbon-carbon double bond to the programme, to optimize a part of the drug molecular synthesis strategy, improve the synthesis efficiency, reduce the cost, with industrial synthetic value and prospects. (by machine translation)
Diastereoselective synthesis of 3-fluoro-2-substituted piperidines and pyrrolidines
Gichuhi, Paul N.,Kuriyama, Masami,Onomura, Osamu
, p. 331 - 346 (2014/01/17)
A facile procedure for synthesis of trans-3-fluoro-2-substituted piperidines by utilizing electrophilic fluorination of cyclic enamines and Lewis acid mediated nucleophilic substitution has been developed. Also, optically active trans-2-allyl-3-fluorinate
SUBSTITUTED TRICYCLIC COMPOUNDS WITH ACTIVITY TOWARDS EP1 RECEPTORS
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, (2013/10/22)
The present invention belongs to the field of EPl receptor ligands. More specifically it refers to compounds of general formula (I) having great affinity and selectivity for the EPl receptor. The invention also refers to the process for their preparation, to their use as medicament for the treatment and/or prophylaxis of diseases or disorders mediated by the EPl receptor as well as to pharmaceutical compositions comprising them.
Formal homo-nazarov and other cyclization reactions of activated cyclopropanes
De Simone, Filippo,Saget, Tanguy,Benfatti, Fides,Almeida, Sofia,Waser, Jerome
, p. 14527 - 14538 (2012/02/04)
The Nazarov cyclization of divinyl ketones gives access to cyclopentenones. Replacing one of the vinyl groups by a cyclopropane leads to a formal homo-Nazarov process for the synthesis of cyclohexenones. In contrast to the Nazarov reaction, the cyclization of vinyl-cyclopropyl ketones is a stepwise process, often requiring harsh conditions. Herein, we describe two different approaches for further polarization of the three-membered ring of vinyl-cyclopropyl ketones to allow the formal homo-Nazarov reaction under mild catalytic conditions. In the first approach, the introduction of an ester group α to the carbonyl on the cyclopropane gave a more than tenfold increase in reaction rate, allowing us to extend the scope of the reaction to non-electron-rich aryl donor substituents in the β position to the carbonyl on the cyclopropane. In this case, a proof of principle for asymmetric induction could be achieved using chiral Lewis acid catalysts. In the second approach, heteroatoms, especially nitrogen, were introduced β to the carbonyl on the cyclopropane. In this case, the reaction was especially successful when the vinyl group was replaced by an indole heterocycle. With a free indole, the formal homo-Nazarov cyclization on the C3 position of indole was observed using a copper catalyst. In contrast, a new cyclization reaction on the N1 position was observed with BrAnsted acid catalysts. Both reactions were applied to the synthesis of natural alkaloids. Preliminary investigations on the rationalization of the observed regioselectivity are also reported.
A new and efficient synthesis of derivatives of octahydro-4H-pyrrolo[1,2-c] pyrido[1′,2′-a]imidazole
Rouchaud, Anne,Braekman, Jean-Claude
, p. 2346 - 2353 (2011/06/22)
When diethyl malonate was added to a solution of Δ1- piperideine, generated in situ by oxidative desamination and decarboxylation of L-lysine by N-bromosuccinimide (NBS), formation of the unexpected tricyclic compound 6 (4-diethylmalonyl-octahydro-4H-pyrrolo[1,2-c]pyrido[1′, 2′-a]imidazole)was observed. The structure of 6 was deduced from analysis of its spectroscopic data and was confirmed both by chemical degradation and by total synthesis. We proved that 3-bromo-1-piperideine was implicated in its formation. Moreover, based on this feature, a new and efficient synthesis of 6 was developed. The elaborated pathway was adapted to access derivatives related to 6 that differed in their C-4 substituent. A new and efficient synthesis of derivatives of the tricyclic heterocycle A from lysine is described. A mechanism involving 3-halopiperideines as intermediates and based on a ring contraction followed by Michael reaction is proposed and tested. Copyright
Sodium borohydride-nickel chloride-methanol catalytic system for regioselective reduction of electron-rich conjugated dienes and reductive cleavage of allyl esters involving π-allylnickel intermediates
Yin, Biao-Lin,Cai, Cong-Bi,Lai, Jin-Qiang,Zhang, Ze-Ren,Huang, Li,Xu, Li-Wen,Jiang, Huan-Feng
supporting information; experimental part, p. 3319 - 3324 (2012/01/30)
The regioslective reduction of electron-rich dienes to monoolefins and the reductive cleavage of allyl esters were fulfilled by employing a sodium borohydride-nickel chloride-methanol catalytic system with exceedingly simple manipulations and high functional group tolerability. Both of the reductive reactions may involve π-allylnickel intermediates generated from fresh nickel boride. Copyright
