- Reactions of cyclopropyl aryl ketones with sulfonamides mediated by Zr(OTf)4: Cascade preparation of 5-aryl-3,4-dihydro-2H-pyrrole
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We found that the Lewis acid Zr(OTf)4 can effectively promote the ring-opening reaction of cyclopropyl aryl ketones with sulfonamides. By controlling the reaction conditions, we could obtain the ring-opened products 3 and the cyclized products 5 in moderate to good yields. This process provides a novel and efficient route for the synthesis of 5-aryl-3,4-dihydro-2H-pyrrole in the presence of a Lewis acid.
- Shi, Min,Yang, Yong-Hua,Xu, Bo
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- Synthesis of 2-aryl-1-pyrrolines from arylnitriles
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Aromatic nitriles underwent addition of stabase-protected γ-aminopropylmagnesium bromide to afford the corresponding 1-pyrrolines in one step. Copyright
- Keppens, Marian,De Kimpe, Norbert,Fonck, Gwendolien
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- Iron-Catalyzed Ring Expansion of Cyclobutanols for the Synthesis of 1-Pyrrolines by Using MsONH3OTf
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The synthesis of 1-pyrrolines from cyclobutanol derivatives and an aminating reagent (MsONH3OTf) has been developed. This one-pot procedure achieves C–N bond/C═N bond formation via ring expansion. A series of 1-pyrroline derivatives are synthes
- Zhuang, Daijiao,Gatera, Tharcisse,An, Zhenyu,Yan, Rulong
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p. 771 - 775
(2022/01/20)
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- Synthesis of 1-Pyrroline by Denitrogenative Ring Expansion of Cyclobutyl Azides under Thermal Conditions
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We herein report an efficient and systematic synthesis of 1-pyrrolines from cyclobutyl azides under thermal and neutral conditions. The reaction proceeded without any additional reagents, and nitrogen was generated as the sole by-product. Furthermore, the generated 1-pyrrolines could be continuously transformed into pyrroles, N-Boc-amines, and oxaziridines in an one-pot manner. (Figure presented.).
- Ban, Kazuho,Miki, Yuya,Sajiki, Hironao,Sawama, Yoshinari,Tomita, Naohito
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p. 3481 - 3484
(2021/06/17)
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- Intramolecular Csp3-H/C-C bond amination of alkyl azides for the selective synthesis of cyclic imines and tertiary amines
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The intramolecular Csp3-H and/or C-C bond amination is very important in modern organic synthesis due to its efficiency in the construction of diversified N-heterocycles. Herein, we report a novel intramolecular cyclization of alkyl azides for the synthesis of cyclic imines and tertiary amines through selective Csp3-H and/or C-C bond cleavage. Two C-N single bonds or a CN double bond are efficiently constructed in these transformations. The carbocation mechanism differs from the reported metal nitrene intermediates and therefore enables metal-free and new transformation.
- Jiao, Ning,Li, Xinyao,Luo, Xiao,Song, Song,Wang, Weijin,Wen, Xiaojin
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p. 4482 - 4487
(2020/05/18)
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- Intramolecular Cyclization of Brominated Oxime Ether Promoted with Ytterbium(0) to the Synthesis of Cyclic Imines
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The first utility of ytterbium(0) as a mediating-metal in the intramolecular cyclization of brominated oxime ether was reported in this paper. In contrast to the prior methods, the N–O bond was used as a receptor of nucleophilic reagent, rather than as a source of N-centered radicals. Cyclic imines were obtained in this one-pot reaction with a broad scope of substrates and feasible reaction conditions.
- Wang, Yiqiong,Huang, Fei,Zhang, Songlin
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supporting information
p. 5178 - 5181
(2020/08/13)
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- Iminyl Radicals by Reductive Cleavage of N-O Bond in Oxime Ether Promoted by SmI2: A Straightforward Synthesis of Five-Membered Cyclic Imines
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A new generation method of N-centered radicals from the reductive cleavage of the N-O bond in oxime ether promoted by SmI2 is reported for the first time. The in-situ-generated N-centered radicals underwent intramolecular cyclization to afford five-membered cyclic imines in two manners: N-centered radical addition and N-centered anion nucleophilic substitution. From a synthetic point of view, an efficient synthetic method of five-membered cyclic imines was developed. A mechanism of the transformation was proposed.
- Huang, Fei,Zhang, Songlin
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supporting information
p. 7430 - 7434
(2019/10/11)
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- Method for synthesizing pyrroline compounds through iron-catalyzed amino alcohol and enol
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The invention discloses a method for synthesizing pyrroline compounds through iron-catalyzed amino alcohol and enol. In the atmosphere of inert gas, the amino alcohol and the enol serve as raw materials, potassium tert-butoxide is used as alkali, a series
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Paragraph 0026; 0027; 0028; 0029; 0086-0089
(2019/05/22)
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- Palladium-catalyzed ortho-olefination of 2-arylpyrrolidines: A tool for increasing structural complexity in nitrogen heterocycles
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The dual role of the (2-pyridyl)sulfonyl unit as directing functionality and readily removable N-protecting group has enabled an efficient and practical transformation of 2-arylpyrrolidine derivatives into more complex tricyclic frameworks via palladium-catalyzed ortho-olefination with electron deficient alkenes and subsequent cyclization upon N-deprotection under mild conditions. The key cross coupling step in the presence of N-fluoro-2,4,6-trimethylpyridinium triflate ([F+]) as the terminal oxidant is both highly efficient and tolerant to a variety of steric and electronic changes at both coupling partners. By adequate choice of reductive conditions, the N-sulfonyl deprotection can be directed to the selective formation of benzo-fused pyrrolizidine or fused pyrrolidino-benzazapine frameworks.
- Legarda, Pablo D.,García-Rubia, Alfonso,Arrayás, Ramón Gómez,Carretero, Juan C.
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p. 3947 - 3954
(2018/06/11)
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- The reaction of cyclic imines with the Ruppert-Prakash reagent. Facile approach to α-trifluoromethylated nornicotine, anabazine, and homoanabazine
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We have demonstrated that the Ruppert-Prakash reagent is able to react with a number of cyclic imines under acidic condition to afford the corresponding α-trifluoromethyl derivatives of nitrogen heterocycles. 5-7-Membered cyclic imines bearing various alkyl, aryl or heterocyclic group were successfully involved in this transformation. Novel trifluoromethylated analogues of nicotine, anabasine, and homoanabasine alkaloids were synthesized.
- Shevchenko, Nikolay E.,Vlasov, Katja,Nenajdenko, Valentine G.,R?schenthaler, Gerd-Volker
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scheme or table
p. 69 - 74
(2011/02/27)
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- Highly effective asymmetric hydrogenation of cyclic N -alkyl imines with chiral cationic Ru-MsDPEN catalysts
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A range of cyclic N-alkyl imines were efficiently hydrogenated by using a chiral cationic Ru(η6-cymene)(MsDPEN)(BArF) complex (MsDPEN = N-(methanesulfonyl)-1,2-diphenylethylenediamine) in high yields and up to 98% ee. A one-pot synthesis of chiral 2-phenylpyrrolidine via reductive amination was also developed.
- Chen, Fei,Ding, Ziyuan,Qin, Jie,Wang, Tianli,He, Yanmei,Fan, Qing-Hua
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supporting information; experimental part
p. 4348 - 4351
(2011/10/13)
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- Iridium-catalyzed enantioselective hydrogenation of cyclic imines
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A catalytic complex made from [Ir(COD)Cl]2 [di-μ-chloro- bis(1,5-cyclooctadiene)diiridium(I)] precursor and (S,S)-f-Binaphane ((R,R)-1,1′-bis{(R)-4,5-dihydro-3H-dinaphtho[1,2-c:2′,1′-e] phosphepino}ferrocene) ligand effectively catalyzed the en
- Chang, Mingxin,Li, Wei,Hou, Guohua,Zhang, Xumu
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supporting information; experimental part
p. 3121 - 3125
(2011/02/22)
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- Diastereoselective synthesis of cyclic 1,3-aminoalcohols bearing CF3(CCl3)-groups
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An aldol-type reaction of cyclic imines and cyclic lactims with carbonyl compounds activated by electron withdrawing trifluoromethyl or trichloromethyl groups proceeded without any catalyst under mild condition. β-Hydroxymethyl substituted cyclic imines or imidates are formed as a result of the reaction. The reduction of the prepared imines leads stereoselectively to the cyclic 1,3-aminoalcohols. Application of methyl trifluoropyruvate in this transformation opens an opportunity for the synthesis of γ-aminoacids derivatives which contain pyrrolidine moiety.
- Shevchenko, Nikolay E.,R?schenthaler, Gerd-Volker,Mitiaev, Alexander S.,Lork, Enno,Nenajdenko, Valentine G.
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scheme or table
p. 637 - 644
(2009/04/03)
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- Convenient synthesis of melatonin analogues: 2- and 3-substituted -N-acetylindolylalkylamines
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A new method for the synthesis of 2- and 3-substituted indolylalkylamides, derivatives of melatonin, from arylhydrazines and amidoketones by the Fischer reaction was elaborated. The amidoketones can be easily prepared from cyclic imines by reaction with acylpyridinium chloride. This method is a one-step synchronous creation of the selected alkylamide fragment and the indole core. Variation of the arylhydrazines create the desired substituents in the carbocycle of indolylalkylamides and suitable choice of amidoketone can direct the amidoalkyl chain to the 2- or 3-position of the indole. Graphical Abstract
- Nenajdenko, Valentine G.,Zakurdaev, Eugene P.,Prusov, Eugene V.,Balenkova, Elizabeth S.
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p. 11719 - 11724
(2007/10/03)
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- A new methodology for the reductive cyclization of ω-azido carbonyl compounds mediated by tetrathiomolybdate: Application to an efficient synthesis of pyrrolo[2,1-c][1,4]benzodiazepines
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The ω-azido carbonyl compounds on treatment with tetrathiomolybdate, 1 led to the formation of 5, 6 and 7 membered cyclic imines in very good yields under mild conditions. This method is applied successfully to a new efficient synthesis of 1,4-benzodiazap
- Prabhu, Kandikere R.,Sivanand,Chandrsekaran, Srinivasan
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- Synthesis of 3-halopyrroles
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3-Chloro- and 3-bromo-2-arylpyrroles, which are potential physiologically active compounds in agrochemistry and pharmaceutical sciences, were efficiently prepared from the corresponding 2-aryl-1-pyrrolines by α,α-dihalogenation with N-halosuccinimides and
- De Kimpe, Norbert,Tehrani, Kourosch Abbaspour,Stevens, Christian,De Cooman, Paul
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p. 3693 - 3706
(2007/10/03)
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- PHOTOCYCLOADDITIONS OF ELECTRON POOR OLEFINS TO 2-ARYL-1-PYRROLINIUM SALTS
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Photocycloadditions of the electron poor olefins, acrylonitrile and methyl acrylate to a series of para-substituted 2-phenyl-1-pyrrolinium perchlorates have been explored as part of studies designed to test new synthetic methods.
- Mariano, Patrick S.,Leone-Bay, Andrea
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p. 4581 - 4584
(2007/10/02)
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