- Synthesis of Eight-Membered Nitrogen Heterocycles via a Heterogeneous PtI2-Catalyzed Cascade Cycloaddition Reaction of δ-Aminoalkynes with Electron-Deficient Alkynes
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A novel heterogeneous PtI2-catalyzed cascade reaction of δ-aminoalkynes was developed for the synthesis of various eight-membered nitrogen heterocycles in excellent yields. The reaction proceeds via a hydration of δ-aminoalkynes and subsequent intramolecular cyclization and intermolecular addition as well as ring-expansion cascade reaction with another electron-deficient alkynes. This method has the advantages of simple operation and mild reaction conditions. And the simple PtI2 with no any supports could be readily recycled through simple centrifugation without substantial loss of activity in 1,2-dichloroethane (DCE). The recyclability of PtI2 may be ascribed to its insolubility in DCE. The reaction constitutes a formal [6+2]-cycloaddition. (Figure presented.).
- Li, Xinhong,Wang, Songmeng,Wang, Hongkai,Wang, Weilin,Liu, Lingyan,Chang, Weixing,Li, Jing
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p. 1525 - 1531
(2020/03/23)
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- Iridium-Catalyzed Hydrochlorination and Hydrobromination of Alkynes by Shuttle Catalysis
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Described herein are two different methods for the synthesis of vinyl halides by a shuttle catalysis based iridium-catalyzed transfer hydrohalogenation of unactivated alkynes. The use of 4-chlorobutan-2-one or tert-butyl halide as donors of hydrogen halides allows this transformation in the absence of corrosive reagents, such as hydrogen halides or acid chlorides, thus largely improving the functional-group tolerance and safety profile of these reactions compared to the state-of-the-art. This method has granted access to alkenyl halide compounds containing acid-sensitive groups, such as tertiary alcohols, silyl ethers, and acetals. The synthetic value of those methodologies has been demonstrated by gram-scale synthesis where low catalyst loading was achieved.
- Yu, Peng,Bismuto, Alessandro,Morandi, Bill
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supporting information
p. 2904 - 2910
(2020/01/25)
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- Nitrogen-containing octatomic ring alkyne derivative and preparation method thereof
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The invention relates to a nitrogen-containing octatomic ring alkyne derivative and a preparation method thereof. The chemical structural formula of the nitrogen-containing octatomic ring alkyne derivative is shown in the description, wherein R is alkyl o
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- Synthesis of spiroaminals by bimetallic Au/Sc relay catalysis: TMS as a traceless controlling group
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An efficient synthesis of spiroaminals over fused aminals has been successfully developed by bimetallic Au/Sc catalysis by using TMS as a traceless controlling group. This journal is
- Zhang, Shuo,Xu, Zhengliang,Jia, Jiong,Tung, Chen-Ho,Xu, Zhenghu
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p. 12084 - 12087
(2014/12/12)
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- Synthesis of fused bicyclic aminals through sequential gold/Lewis acid catalysis
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A novel sequential catalysis by combining gold catalysis with early transition metal catalysis was developed. Biologically important bicyclo[4.n.0] aminals were obtained under very mild conditions.
- Wang, Xi'Anghua,Yao, Zhili,Dong, Shuli,Wei, Fang,Wang, Hong,Xu, Zhenghu
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supporting information
p. 2234 - 2237
(2013/06/27)
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- Reductive cyclization of bromoenynamides with alcohols as hydride source: Synthesis and reactions of 2-amidodienes
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Under basic conditions in alcoholic solvents, bromoenynamides undergo palladium-catalyzed cyclization to cyclic 2-amidodienes in good to excellent yields. This process represents the first use of an alcohol as a hydride source in an alkyne carbopalladation/termination sequence, with the site selectivity of the reduction showing a strong dependence on the tethering ring size (5-8), and the nature of the alcohol and base. Reaction of the dienes with a range of dienophiles (including alkenes, alkynes and arynes) under various conditions gives bi- and tricyclic azacycles, which can be further oxidized to the aromatic azacycles. Copyright
- Greenaway, Rebecca L.,Campbell, Craig D.,Chapman, Helen A.,Anderson, Edward A.
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supporting information
p. 3187 - 3194
(2013/01/15)
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- Regioselective cobalt-catalyzed formation of bicyclic 3- and 4-aminopyridines
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Bimolecular cobalt-catalyzed [2+2+2] cycloadditions between yne-ynamides and nitriles afford bicyclic 3- or 4-aminopyridines in up to 100% yield. The high regioselectivity observed depends on the substitution pattern at the starting ynamide. Aminopyridines bearing TMS and Ts groups are efficiently deprotected in an orthogonal fashion.
- Garcia, Pierre,Evanno, Yannick,George, Pascal,Sevrin, Mireille,Ricci, Gino,Malacria, Max,Auber, C. Torinne,Gandon, Vincent
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p. 2030 - 2033
(2011/06/23)
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- Combination of gold catalysis and Selectfluor for the synthesis of fluorinated nitrogen heterocycles
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We herein report the synthesis of 3-fluoro-2-methylene-pyrrolidine (3a) and -piperidine (3b) from 1,5- and 1,6-aminoalkynes, respectively, using a combination of a gold-catalyzed hydroamination reaction followed by electrophilic trapping of an intermediat
- Simonneau, Antoine,Garcia, Pierre,Goddard, Jean-Philippe,Mouries-Mansuy, Virginie,Malacria, Max,Fensterbank, Louis
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experimental part
p. 1379 - 1386
(2011/11/07)
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- Total synthesis of (+)-nankakurines A and B and (±)-5-epi- nankakurine A
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The first total syntheses of the Lycopodium alkaloids (+)-nankakurine A (2), (+)-nankakurine B (3), and the originally purported structure 1 of nankakurine A were accomplished. The syntheses of 2 and 3 feature a demanding intramolecular azomethine imine cycloaddition as the key step for generating the octahydro-3,5-ethanoquinoline moiety and installing the correct relative configuration at the spiropiperidine ring juncture. The cyclization precursor was prepared from octahydronaphthalene ketone 50, which was assembled from enone (+)-9 and diene 48 by a cationic Diels-Alder reaction. The Diels-Alder reactants were synthesized from 5-hexyn-1-ol (16) and (+)-pulegone (49), respectively. The tetracyclic ring system of 1 was generated using an unprecedented nitrogen-terminated aza-Prins cyclization cascade. The enantioselective total syntheses of (+)-nankakurine A (2) and (+)-nankakurine B (3) establish the relative and absolute configuration of these alkaloids and are sufficiently concise that substantial quantities of 2 and 3 were prepared for biological studies. (+)-Nankakurine A and (+)-nankakurine B showed no effect on neurite outgrowth in rat hippocampal H-19 cells over a concentration range of 0.3-10 μM.
- Altman, Ryan A.,Nilsson, Bradley L.,Overman, Larry E.,Read De Alaniz, Javier,Rohde, Jason M.,Taupin, Veronique
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experimental part
p. 7519 - 7534
(2011/02/23)
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- Enantioselective total syntheses of nankakurines A and B: Confirmation of structure and establishment of absolute configuration
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Total syntheses of (+)-nankakurine A (2) and (+)-nankakurine B (3) were accomplished by a sequence that employs an intramolecular dipolar cycloaddition of an azomethine imine intermediate to form the azatricyclic moiety and establish the relative configur
- Nilsson, Bradley L.,Overman, Larry E.,De Alaniz, Javier Read,Rohde, Jason M.
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p. 11297 - 11299
(2018/02/14)
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- A ruthenium-catalyzed, atom-economical synthesis of nitrogen heterocycles
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The Ruthenium catalyzed, atom-economical domino redox isomerization/cyclization of tethered aminopropargyl alcohols is reported. This process displays a broad scope and functional group tolerance. Furthermore, it presents a novel retrosynthetic disconnect
- Trost, Barry M.,Maulide, Nuno,Livingston, Robert C.
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supporting information; experimental part
p. 16502 - 16503
(2009/04/13)
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- Intramolecular aminopalladation and cross coupling of acetylenic amines
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Stereodefined 2-alkylidene-pyrrolidines and -piperidine were synthesized by treatment of an acetylenic amines with n-BuLi followed by addition of catalytic amount of Pd(OAc)2 and PPh3 in THF and 3 equiv of an organic halide.
- Luo, Fen-Tair,Wang, Ren-Tzong
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p. 6835 - 6838
(2007/10/02)
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