1605-06-7Relevant academic research and scientific papers
On the Mechanism of the Aziridine Synthesis from 2-Azido-alcohols and Triphenylphosphine
Poechlauer, Peter,Mueller, Ernst Peter,Peringer, Paul
, p. 1238 - 1247 (1984)
The reaction of selected 2-azido-alcohols, their pivalates, and methanesulfonates with triphenylphosphine was investigated.It is shown that the formation of aziridines from 2-azido-alcohols proceeds via 1,3,2λ5-oxazaphospholidines.Furthermore, the first synthesis of the unsubstituted acenaphthene-1,2-imine is described.
Chiral sulfide - phosphine ligand and preparation method and use thereof
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Paragraph 0059; 0069; 0079; 0089; 0099; 0109; 0120, (2017/08/25)
The present invention provides a novel chiral thioether-phosphine ligand and a preparation method and application thereof. The ligand is a compound shown as a formula I, or enantiomer, non-enantiomer, racemate, pharmaceutically acceptable salt, hydrate and solvate crystal thereof. R1 is an optionally substituted phenyl, and optionally substituted naphthyl; and R2 is methyl and benzyl. The chiral thioether-phosphine ligand provided by the invention as a copper-catalyzed asymmetric cycloaddition ligand can be directly used to prepare various pyrrolidine compounds with substituted multiple chiral centers.
Enantioselective synthesis of tetrahydrofuran derivatives by sequential henry reaction and iodocyclization of γ,δ-unsaturated alcohols
Chen, Li-Yan,Chen, Jia-Rong,Cheng, Hong-Gang,Lu, Liang-Qiu,Xiao, Wen-Jing
supporting information, p. 4714 - 4719 (2014/08/05)
A sequential one-pot Cu-catalyzed asymmetric Henry reaction and iodocyclization is disclosed. The transformation provides efficient access to biologically and synthetically useful 2,2,5-trisubstituted tetrahydrofuran derivatives. The combination of Cu(OAc)2·H2O with a novel chiral sulfoxide-Schiff base hybrid ligand under mild reaction conditions tolerates a wide range of 4-substituted γ,δ-unsaturated aldehydes, and the subsequent iodocyclization furnishes the corresponding products in generally high yields with excellent enantioselectivities. The products can be easily converted into amines with excellent diastereo- and enantioselectivities.
Activation of carboxylic acids in asymmetric organocatalysis
Monaco, Mattia Riccardo,Poladura, Belen,Diaz De Los Bernardos, Miriam,Leutzsch, Markus,Goddard, Richard,List, Benjamin
, p. 7063 - 7067 (2014/07/08)
Organocatalysis, catalysis using small organic molecules, has recently evolved into a general approach for asymmetric synthesis, complementing both metal catalysis and biocatalysis.1 Its success relies to a large extent upon the introduction of novel and generic activation modes.2 Remarkably though, while carboxylic acids have been used as catalyst directing groups in supramolecular transition-metal catalysis,3 a general and well-defined activation mode for this useful and abundant substance class is still lacking. Herein we propose the heterodimeric association of carboxylic acids with chiral phosphoric acid catalysts as a new activation principle for organocatalysis. This self-assembly increases both the acidity of the phosphoric acid catalyst and the reactivity of the carboxylic acid. To illustrate this principle, we apply our concept in a general and highly enantioselective catalytic aziridine-opening reaction with carboxylic acids as nucleophiles. Activation by dimerization: There is still no general activation mode for carboxylic acids in organocatalysis. The formation of heterodimers between chiral phosphoric acid diesters and carboxylic acids can be used to activate and direct reactivity of the latter in asymmetric reactions. This novel principle has been applied to the ring-opening desymmetrization and kinetic resolution of aziridines leading to valuable amino alcohols.
Design of chiral sulfoxide-Schiff base hybrids and their application in Cu-catalyzed asymmetric Henry reactions
Cheng, Hong-Gang,Lu, Liang-Qiu,Wang, Tao,Chen, Jia-Rong,Xiao, Wen-Jing
supporting information; experimental part, p. 5596 - 5598 (2012/07/03)
A new class of chiral sulfoxide-Schiff base ligands has been developed by the rational combination of two privileged chiral backbones. These sulfoxide-Schiff base ligands were found to be highly efficient for Cu-catalyzed asymmetric Henry reactions (up to
Synthesis and structure of hypervalent diacetoxybromobenzene and aziridination of olefins with imino-λ3-bromane generated in situ under metal-free conditions
Hoque, Md. Mahbubul,Miyamoto, Kazunori,Tada, Norihiro,Shiro, Motoo,Ochiai, Masahito
, p. 5428 - 5431 (2011/11/30)
Ligand exchange of p-CF3C6H4BrF 2 with acetoxy groups using AcOH and Ac2O affords (diacetoxybromo)benzene in a high yield, which undergoes aziridination of alkenes in the presence of TfNH2
2-(p-Tolylsulfinyl)benzyl halides as efficient precursors of optically pure trans-2,3-Disubstituted aziridines
Arroyo, Yolanda,Meana, Angela,Sanz-Tejedor, M. Ascension,Alonso, Ines,Garcia Ruano, Jose Luis
experimental part, p. 9874 - 9883 (2010/10/04)
Aziridination of (R)-N-sulfinylaldimines (aryl, heteroaryl and alkenyl derivatives) with 2-(p-tolyl sulfinyl)benzyl iodide in the presence of sodium hexamethyl disilazide takes place with almost complete control of the stereoselectivity (facial and antil
Stereoselective control of planar α-dimethylsulfonium benzyl carbanions. Synthesis of optically pure trans-aziridines
Arroyo, Yolanda,Meana, Angela,Rodriguez, J. Felix,Sanz-Tejedor, M. Ascension,Alonso, Ines,Ruano, Jose L. Garcia
experimental part, p. 4217 - 4224 (2009/09/25)
(Chemical Equation Presented) (R)-N-Sulfinylimine and (S)-N-sulfinylimine react with the ylide derived from (S)-dimethyl-[2-(p-toluenesulfinyl) phenyl]sulfonium salt, affording trans-2,3-disubstituted aziridines. A complete trans selectivity in low facial
Bronsted acid-catalyzed desymmetrization of meso-aziridines
Rowland, Emily B.,Rowland, Gerald B.,Rivera-Otero, Edwin,Antilla, Jon C.
, p. 12084 - 12085 (2008/04/11)
The enantioselective ring-opening of meso-aziridines with azide nucleophiles proceeded in the presence of a catalytic amount of a chiral phosphoric acid catalyst. The reaction affords the formation of the products in excellent yield and enantioselectivity. Preliminary mechanistic studies indicate that the active catalytic species is a chiral silane that is generated in situ. Copyright
Aminosulf(ox)ides as Ligands for Iridium(I)-Catalyzed Asymmetric Transfer Hydrogenation
Petra, Danielle G. I.,Kamer, Paul C. J.,Spek, Anthony L.,Schoemaker, Hans E.,Van Leeuwen, Piet W. N. M.
, p. 3010 - 3017 (2007/10/03)
A new class of efficient catalysts was developed for the asymmetric transfer hydrogenation of unsymmetrical ketones. A series of chiral N,S-chelates (6-22) was synthesized to serve as ligands in the iridium(I)-catalyzed reduction of ketones. Both formic a
