Synthesis of an Inherently Chiral Calix[4]arene Amino Acid and Its Derivatives: Their Application to Asymmetric Reactions as Organocatalysts

2009 ◽  
Vol 2009 (12) ◽  
pp. 1916-1924 ◽  
Author(s):  
Seiji Shirakawa ◽  
Shoichi Shimizu
Keyword(s):  
Amino Acid ◽  
Asymmetric Reactions ◽  
Inherently Chiral

Synthesis and optical resolution of an inherently chiral calix[4]arene amino acid

2008 ◽  
Vol 32 (11) ◽  
pp. 1835 ◽  
Author(s):  
Seiji Shirakawa ◽  
Yuichi Tanaka ◽  
Takafumi Kobari ◽  
Shoichi Shimizu
Keyword(s):  
Amino Acid ◽  
Optical Resolution ◽  
Inherently Chiral

scholarly journals Stereodivergent entry to β-branched β-trifluoromethyl α-amino acid derivatives by sequential catalytic asymmetric reactions

2021 ◽  
Author(s):  
Vasco Corti ◽  
Riccardo Riccioli ◽  
Ada Martinelli ◽  
Sofia Sandri ◽  
Mariafrancesca Fochi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Asymmetric Reactions ◽  
Amino Acid Derivatives ◽  
One Pot ◽  
Catalytic Asymmetric ◽  
Catalytic Asymmetric Reactions

Currently, conventional reductive catalytic methodologies do not guarantee general access to enantioenriched β-branched β-trifluoromethyl α-amino acid derivatives. Herein, a one-pot approach to these important α-amino acids, grounded on the reduction...

Asymmetric Reactions with Amino Acid Based Chiral Acyloxyboranes

2005 ◽  
pp. 1
Author(s):  
M. Periasamy ◽  
M. N. Reddy ◽  
N. S. Kumar
Keyword(s):  
Amino Acid ◽  
Asymmetric Reactions

Silver-catalyzed asymmetric amination of silyl enol ethers

2000 ◽  
Vol 78 (6) ◽  
pp. 666-672 ◽  
Author(s):  
Yasuhiro Yamashita ◽  
Haruro Ishitani ◽  
Shu Kobayashi
Keyword(s):  
Catalytic Activity ◽  
Amino Acid ◽  
Asymmetric Synthesis ◽  
Asymmetric Reactions ◽  
High Catalytic Activity ◽  
Enol Ethers ◽  
Chiral Catalyst ◽  
Silyl Enol Ethers ◽  
Catalytic Amination

Catalytic amination of silyl enol ethers with azo diester compounds was investigated. It was shown that Cu(OTf)2 or AgOTf had high catalytic activity and that AgOTf was the most efficient among the catalysts tested in the reactions. In asymmetric reactions, the AgClO4-BINAP system showed high enantioselectivity. In a mixture of toluene or mesitylene and THF, silyl enol ethers reacted with dibenzyl azodicarboxylate (DBnAD) smoothly to afford the corresponding amination adducts in excellent yields with up to 86% ee.Key words: amination, amino acid, asymmetric synthesis, chiral catalyst, silver.

The staining pattern of the tropomyosin sequence is displayed in a new paracrystal

1986 ◽  
Vol 44 ◽  
pp. 150-151
Author(s):  
M.K. Lamvik ◽  
L.L. Klatt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Staining Pattern ◽  
Banding Patterns ◽  
Mass Thickness ◽  
New Form

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

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