119244-23-4Relevant articles and documents
Synthesis of chiral ionic polymers containing quaternary ammonium sulfonate structure and their catalytic activity in asymmetric alkylation
Parvez, Masud,Salam, Abdus,Haraguchi, Naoki,Itsuno, Shinichi
, p. 815 - 821 (2012)
Repeated reaction between chiral quaternary ammonium dimer and disodium disulfonate gave the ionic polymer, which contains chiral quaternary ammonium sulfonate structure as a repeating unit. This chiral ionic polymer showed an excellent catalytic activity
Main-chain ionic chiral polymers: Synthesis of optically active quaternary ammonium sulfonate polymers and their application in asymmetric catalysis
Itsuno, Shinichi,Paul, Devproshad K.,Salam, M. A.,Haraguchi, Naoki
, p. 2864 - 2865 (2010)
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A convenient method for asymmetric alkylation of glycine imine esters using solid supports
Yu, Haitao,Koshima, Hideko
, p. 9209 - 9212 (2003)
Asymmetric alkylation of butyl glycinate-benzophenone Schiff base proceeded smoothly on clays and alumina at room temperature to afford alkylated products in high yields and good enantioselectivities.
A Simple Chiral Cu(II) Complex as an Effective Phase-Transfer Catalyst for the Enantioselective Alkylation of Dissymmetric Glycinate Ketimines
Bafqiren, Hanane,Zouihri, Hafid,Gmouh, Said,Jamal Eddine, Jamal
, p. 944 - 950 (2015)
Catalytic asymmetric benzylation of a dissymmetric tert-butylglycinate ketimine, incorporating 1-naphthyl and phenyl groups as the Schiff base substituents, under phase-transfer conditions was investigated. It was interesting to note that the sense of asymmetric induction of the alkylation of Z-imine stereoisomer is opposite to that of the corresponding E stereoisomer with a similar degree of enantioselectivity. More interestingly, the chiral Cu(II) complex of the Schiff base derived from (R)-2-phenylglycinol and 2-hydroxy-1-naphthaldehyde was found to catalyze the same reaction under solid-liquid conditions with comparable enantioselectivity (up to 60% ee) with respect to known cinchona alkaloid catalysts. The solvent/base-system parameter was shown to control the optimal catalytic activity. Chirality 27:944-950, 2015.
Design of new polyamine-based chiral phase-transfer catalysts for the enantioselective synthesis of phenylalanine
Kano, Taichi,Konishi, Shunsuke,Shirakawa, Seiji,Maruoka, Keiji
, p. 1243 - 1245 (2004)
Enantiomerically enriched phenylalanine was synthesized by asymmetric benzylation of a glycine Schiff base using polyamine-based chiral phase-transfer catalysts.
Synthesis of cinchona alkaloid-derived chiral polymers by Mizoroki-Heck polymerization and their application to asymmetric catalysis
Parvez, Md. Masud,Haraguchi, Naoki,Itsuno, Shinichi
, p. 1922 - 1928 (2014)
To facilitate the asymmetric catalysis process, we designed novel polymeric chiral catalysts. Since quaternary ammonium salts of cinchona alkaloid derivatives show efficient catalytic activity in various asymmetric transformations, we have synthesized nov
Synthesis of main-chain chiral quaternary ammonium polymers for asymmetric catalysis using quaternization polymerization
Haraguchi, Naoki,Ahamed, Parbhej,Parvez, Masud,Itsuno, Shinichi
, p. 7569 - 7583 (2012)
Main-chain chiral quaternary ammonium polymers were successfully synthesized by the quaternization polymerization of cinchonidine dimer with dihalides. The polymerization occurred smoothly under optimized conditions to give novel type of main-chain chiral quaternary ammonium polymers. The catalytic activity of the polymeric chiral organocatalysts was investigated on the asymmetric benzylation of N-(diphenylmethylidene)glycine tert-butyl ester.
Development of a recyclable fluorous chiral phase-transfer catalyst: Application to the catalytic asymmetric synthesis of α-amino acids
Shirakawa, Seiji,Tanaka, Youhei,Maruoka, Keiji
, p. 1429 - 1431 (2004)
A recyclable fluorous chiral phase-transfer catalyst was synthesized and successfully applied for the catalytic asymmetric synthesis of both natural and unnatural α-amino acids. The reaction involves alkylation of a glycine derivative followed by extractive recovery of the chiral phase-transfer catalyst using fluorous solvent.
Counter-rotatable dual cinchona quinuclidinium salts and their phase transfer catalysis in enantioselective alkylation of glycine imines
Nahm, Keepyung,Oh, Jiin,Park, Jihyeon
supporting information, p. 6816 - 6819 (2021/07/13)
Dual cinchona quinuclidinium salts with a diphenyl ether linker were synthesized and used as powerful asymmetric phase transfer catalysts in the α-alkylation of imines of glycine and alanine ester with 0.01-0.1 mol% loading (17 examples, 92-99% ee). Skewed conformers of dual quinuclidiniums at TS were proposed to rationalize their high efficiencyviaDFT calculations.
Scandium(III) Triflate Catalyzed Direct Synthesis of N-Unprotected Ketimines
Hirazawa, Yoshinobu,Kadota, Tetsuya,Kondo, Yuta,Morimoto, Hiroyuki,Morisaki, Kazuhiro,Ohshima, Takashi
supporting information, p. 120 - 125 (2020/02/20)
N-Unprotected ketimines are useful substrates and intermediates for synthesizing valuable nitrogen-containing compounds, but their potential applicability is limited by the available synthetic methods. To address this issue, we report a scandium(III) triflate catalyzed direct synthesis of N-unprotected ketimines. Using commercially available reagents and Lewis acid catalysts, ketones were directly transformed into the corresponding N-unprotected ketimines in high yields with broad functional group tolerance, even in multigram scales. The reactions were readily applicable for one-pot synthesis of important compounds such as a glycine Schiff base without isolation of N-unprotected ketimine intermediates. Preliminary mechanistic studies to clarify the reaction mechanism are also described.
Amide-Based Cinchona Alkaloids as Phase-Transfer Catalysts: Synthesis and Potential Application
Majdecki, Maciej,Niedbala, Patryk,Jurczak, Janusz
supporting information, p. 8085 - 8090 (2019/10/14)
Herein we present a library of simple amide derivatives of Cinchona alkaloids in the form of quaternary ammonium salts. The obtained derivatives can be generated very easily and efficiently from inexpensive and commercially available substrates. We tested this class of alkaloids in the alkylation of glycine derivative, carried out under phase-transfer catalyst conditions. The presented hybrid catalysts offer both high reaction yields (up to 97%) and high enantioselectivities of the obtained product (up to 94% ee).
