95683-62-8Relevant academic research and scientific papers
One-Pot Reductive 1,3-Dipolar Cycloaddition of Secondary Amides: A Two-Step Transformation of Primary Amides
Huang, Pei-Qiang,Lang, Qi-Wei,Hu, Xiu-Ning
, p. 10227 - 10235 (2016/11/17)
The one-pot reductive 1,3-dipolar cycloaddition of secondary aromatic N-(trimethylsilylmethyl)amides with reactive dipolarophiles is reported. The method relies on the in situ generation of nonstabilized NH azomethine ylide dipoles via amide activation with triflic anhydride, partial reduction with 1,1,3,3-tetramethyldisiloxane (TMDS), and desilylation with cesium fluoride (CsF). Running under mild conditions, the reaction tolerated several sensitive functional groups and provided cycloadducts in 71-93% yields. The use of less reactive dipolarophile methyl acrylate led to the cycloadduct in only 40% yield. A (Z) geometric intermediate of NH-azomethine 1,3-dipole was postulated to account for the observed higher yields and higher cis diastereoselectivity for the substrates bearing an electron-withdrawing group. This model features an unconventional cyclic transition state via carbanion-aryl ring interaction. Because the starting secondary amides can be prepared from common primary amides, the current method also constitutes a two-step transformation of primary amides.
Synthesis of β-prolinols via [3+2] cycloaddition and one-pot programmed reduction: Valuable building blocks for polyheterocycles
Li, Jundong,Lin, Na,Yu, Lei,Zhang, Yandong
supporting information, p. 5777 - 5780 (2016/12/06)
A novel two-step synthesis of multisubstituted β-prolinols has been developed, featuring a [3+2] cycloaddition of azomethine ylides and a programmed reduction triggered by the combination of borane and lithium aluminum hydride (LAH). β-Prolinols are shown to be valuable building blocks for polyheterocycles.
Rhodium-Catalyzed Intramolecular C-H Bond Activation with Triazoles: Preparation of Stereodefined Pyrrolidines and Other Related Cyclic Compounds
Senoo, Masato,Furukawa, Ayana,Hata, Takeshi,Urabe, Hirokazu
supporting information, p. 890 - 895 (2016/01/16)
On treatment of triazoles having an N-sulfonyl-protected benzylamine moiety with [Rh2(C7H15CO2)4], intramolecular C-H bond insertion takes place at the benzylic position to give cis-N-sulfonyl-2-aryl-3-[(sulfonylimino)methyl]pyrrolidines in good yields and with highly stereoselectivities. Analogously, the similar treatment of triazoles having an ether or even an alkyl moiety affords 2-alkyl- or 2-aryl-3-[(sulfonylimino)methyl]tetrahydrofurans or a 2-alkyl-3-[(sulfonylimino)methyl]cyclopentane in good yields. Three is a magic number: On treatment of triazoles with [Rh2(C7H15CO2)4], the rhodium catalyst plays three roles, denitrogenation, C-H bond activation, and stereoselective cyclization, providing a new method for heterocycle synthesis. Intramolecular C-H bond insertion takes place at the benzylic position to give pyrrolidines and related heterocycles in good yields.
The Cyano Group as a Traceless Activation Group for the Intermolecular [3+2] Cycloaddition of Azomethine Ylides: A Five-Step Synthesis of (±)-Isoretronecanol
Li, Jundong,Zhao, Huaibo,Jiang, Xunjin,Wang, Xiance,Hu, Haiming,Yu, Lei,Zhang, Yandong
supporting information, p. 6306 - 6310 (2015/05/20)
The cyano group was used as a traceless activation group for the [3+2] cycloaddition of azomethine ylides in a two-step process, thereby providing a highly effective approach to 5-unsubstituted pyrrolidines. The transformation includes the silver acetate
Synthesis of cis-2-aryl-3-pyrrolidine carboxylic esters via diastereoselective cyclization of γ-imino esters using a TiCl 4/Et3N reagent system
Suresh, Surisetti,Periasamy, Mariappan
, p. 6291 - 6293 (2007/10/03)
Facile synthesis of cis-2-aryl-3-pyrrolidine carboxylates from readily accessible γ-imino esters by intramolecular cyclization mediated by a TiCl4/Et3N reagent system is described.
One-Pot Synthesis of N-Alkylpyrrolidines by 1,3-Dipolar Cycloaddition
Imai, Nobuyuki,Achiwa, Kazuo
, p. 593 - 601 (2007/10/02)
N-Alkylpyrrolidines were obtained by one-pot synthesis through 1,3-dipolar cycloaddition of the N-alkylazomethine ylide intermediates generated from N-(benzylidene)trimethylsilylmethylamine and alkyl halide or tosylate.
The Origin of Regio- and Stereoselectivities in 1,3-Cycloadditions of Azomethine Ylides Generated from N-(Benzylidene)trimethylsilylmethylamine and the Related Compounds
Imai, Nobuyuki,Tokiwa, Hiroaki,Akahori, Yukio,Achiwa, Kazuo
, p. 1113 - 1116 (2007/10/02)
The frontier molecular orbital theory (ab initio procedures) was found to clearly explain the regio- and stereoselectivities in 1,3-dipolar cycloadditions of the azomethine ylides to conjugated olefins yielding the pyrrolidines.
Trimethylsilyl Triflate-Catalyzed 1,3-Dipolar Cycloaddition Leading to N-Unsubstituted Pyrrolidines
Achiwa, Kazuo,Sugiyama, Kaori,Sekiya, Minoru
, p. 1975 - 1981 (2007/10/02)
Dipolar cycloaddition of an intermediary N-trimethylsilyltrimethylsilylmethyliminium salt formed from N-(benzylidene)trimethylsilylmethylamine by the catalytical action of trimethylsilyl triflate to conjugated alkene or alkyne gave N-unsubstituted pyrroli
1,3-DIPOLAR CYCLOADDITION LEADING TO N-ALKYLPYRROLIDINES
Achiwa, Kazuo,Imai, Nobuyuki,Inaoka, Tetsuya,Sekiya, Minoru
, p. 2878 - 2881 (2007/10/02)
1,3-Dipolar cycloaddition of an intermediary methyleneiminium ylide formed from N-(benzylidene)trimethylsilylmethylamine and alkyl halide to conjugated olefinic dipolarophiles has been found to give N-alkylpyrrolidines.KEYWORDS - N-alkylpyrrolidine; N-unsubstituted pyrrolidine; 1,3-dipolar cycloaddition; N-alkyltrimethylsilylmethyliminium salt; methyleneiminium ylide
HIGH REGIOSELECTIVITIES IN 1,3-CYCLOADDITION OF INTERMEDIARY CARBANIONS PROMOTED BY TETRABUTYLAMMONIUM FLUORIDE AND AZOMETHINE YLIDE CATALYZED BY TRIFLUOROACETIC ACID
Achiwa, Kazuo,Imai, Nobuyuki,Motoyama, Tadashi,Sekiya, Minoru
, p. 2041 - 2044 (2007/10/02)
Tetrabutylammonium fluoride catalytically induced a regioselective 1,3-cycloaddition of the carbanions leading to 2,2,4-substituted pyrrolidines.And in the presence of trifluoroacetic acid, the corresponding 2,2,3-substituted products were regioselectivel
