- Directed Copper-Catalyzed Intermolecular Aminative Difunctionalization of Unactivated Alkenes
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A diverse collection of copper-catalyzed intermolecular aminative difunctionalizations of unactivated alkenes with N-halodialkylamines as the terminal dialkylamino source is reported. A bidentate auxiliary tethered on the alkene substrates is crucial, which can promote the migratory insertion of nonactivated alkenes into the aminyl radical-metal complex and stabilize the resultant high-valent copper intermediate to allow for further transformations. By employing this strategy, the intermolecular aminohalogenation reactions and a three-component aminoazidation reaction of unactivated alkenes with dialkylamino source were successively achieved in a remarkable regio- and stereoselective manner. These reactions were performed under neutral conditions and maintained excellent functional group tolerance toward a wide range of N-halodialkylamines and unactivated alkenes. Further mechanistic studies and DFT calculations supported a concerted migratory insertion of the C-C double bond into the aminyl radical-metal complex to form a Cu(III) intermediate.
- Li, Yang,Liang, Yujie,Dong, Junchao,Deng, Yi,Zhao, Chunyang,Su, Zhongmin,Guan, Wei,Bi, Xihe,Liu, Qun,Fu, Junkai
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- Understanding the Alkylation Mechanism of 3-Chloropiperidines – NMR Kinetic Studies and Isolation of Bicyclic Aziridinium Ions
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The present study describes the kinetic analysis of the 3-chloropiperidine alkylation mechanism. These nitrogen mustard-based compounds are expected to react via a highly electrophilic bicyclic aziridinium ion, which is readily attacked by nucleophiles. Halide abstraction using silver salts with weakly coordinating anions lead to the isolation of these proposed intermediates, whereas their structure was confirmed by single crystal XRD. Kinetic studies of the aziridinium ions also revealed notable reactivity differences of the C5 gem-methylated compounds and their unmethylated counterparts. The observed reactivity trends were also reflected by NMR studies in aqueous solution and DNA alkylation experiments of the related 3-chloropiperidines. Therefore, the underlying Thorpe-Ingold effect might be considered as another option to adjust the alkylation activity of these compounds.
- Helbing, Tim,Georg, Mats,St?hr, Fabian,Carraro, Caterina,Becker, Jonathan,Gatto, Barbara,G?ttlich, Richard
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p. 5905 - 5913
(2021/10/29)
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- Transition metal-free iodine-promoted haloamination of unfunctionalized olefins
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A transition metal-free route to 3-halopiperidines and 2- halomethylpiperidines was described. In the presence of iodine, potassium persulfate and a suitable halogen source, intramolecular haloamination of 4-penten-1-amines and 5-hexen-1-amines proceeded readily, leading to the corresponding substituted piperidines in good isolated yields. This journal is the Partner Organisations 2014.
- Li, Wei,Liu, Gong-Qing,Cui, Bin,Zhang, Li,Li, Ting-Ting,Li, Lin,Duan, Lili,Li, Yue-Ming
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p. 13509 - 13513
(2014/04/03)
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- One-pot preparation of 3-chloropiperidine compounds via Cu(II)-promoted intramolecular chloroamination of unfunctionalized olefins
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3-Chloropiperidine compounds were obtained via Cu(II)-promoted one-pot intramolecular chloroamination of N-benzyl-4-penten-1-amines and subsequent rearrangement. The reaction conditions leading to this skeleton were studied, and the structure of the product was confirmed by NMR as well as X-ray diffraction experiments.
- Li, Run-Lin,Liu, Gong-Qing,Li, Wei,Wang, Yu-Mei,Li, Lin,Duan, Lili,Li, Yue-Ming
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p. 5867 - 5873
(2013/07/27)
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- A new method for intramolecular chloroamination of unfunctionalized olefins
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A new method for the intramolecular chloroamination of unfunctionalized olefins is reported. The reactions were carried out at room temperature for 3 h using hydrated copper(II) chloride as both promoter and chlorine source, and the corresponding vincinal haloamines were obtained in good isolated yields.
- Liu, Gong-Qing,Li, Wei,Li, Yue-Ming
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supporting information
p. 395 - 402
(2013/05/08)
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- Rearrangement of β-chloro N-oxides to hydroxylamines: Opening of the oxazetidinium intermediate by different nucleophiles
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The rearrangement of β-chloro N-oxides to hydroxylamines is stereospecific in accord with the presence of a cyclic oxazetidinium intermediate. The latter opens with a range of nucleophiles (carboxylates, cyanide, azide, and thiols)
- Wefelscheid, Ulrike K.,Woodward, Simon
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supporting information; experimental part
p. 2254 - 2256
(2009/08/07)
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- Synthesis and reaction of 1-azabicyclo[3.1.0]hexane
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The effective formation of 1-azabicyclo[3.1.0]hexane (5) by treatment of 2-(bromomethyl)pyrrolidine hydrobromide (4) with n-BuLi was established, with the reaction occurring by a rational reaction pathway via the open chain transition state 8 based on int
- Hayashi, Kazuhiko,Kujime, Eiko,Katayama, Hajime,Sano, Shigeki,Shiro, Motoo,Nagao, Yoshimitsu
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experimental part
p. 1142 - 1146
(2010/03/31)
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- Ring expansion - Formation of optically active 3-hydroxypiperidines from pyrrolidinemethanol derivatives
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Treatment of pyrrolidinemethanol derivatives (-)-1, (-)-6, (-)7, 8, (- )-9, (+)-10, (-)-11, and (-)-21 with trifluoroacetic anhydride and then with Et3N afforded, after hydrolysis of the trifluoroacetyl group with NaOH, the optically active -hy
- Cossy, Janine,Dumas, Cecile,Gomez Pardo, Domingo
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p. 1693 - 1699
(2007/10/03)
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- Formation of Optically Active 3-Hydroxypiperidines
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The synthesis of enantiomerically pure 3-hydroxypiperidines has been achieved from prolinol.
- Cossy, Janine,Dumas, Cecile,Michel, Patrick,Pardo, Domingo Gomez
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p. 549 - 552
(2007/10/02)
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