An insight into the synthesis of novel aryl-substituted alicyclic β-amino acid derivatives through substrate-directed palladium-catalysed regio- and stereoselective cross-coupling

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13628-13634 ◽  
Author(s):  
Melinda Nonn ◽  
Loránd Kiss ◽  
Mikko M. Hänninen ◽  
Ferenc Fülöp
Keyword(s):  
Amino Acid ◽  
Cross Coupling ◽  
Amino Acid Derivatives ◽  
Amino Esters ◽  
Aryl Iodides ◽  
Insight Into

Novel aryl-substituted alicyclic β-amino acid derivatives were synthesized through substrate-determined palladium-catalysed cross-coupling of aryl iodides with five- or six-membered cycloalkene β-amino esters.

Complexation of Fluorinated Amino Acid Derivatives by β- and γ-Cyclodextrin in Aqueous Solution. A 19F Nuclear Magnetic Resonance Study

1995 ◽  
Vol 48 (3) ◽  
pp. 505 ◽  
Author(s):  
SE Brown ◽  
CJ Easton ◽  
SF Lincoln
Keyword(s):  
Aqueous Solution ◽  
Amino Acid ◽  
Nuclear Magnetic Resonance Study ◽  
Amino Acid Derivatives ◽  
Magnetic Resonance Study ◽  
Cyclodextrin Complexes ◽  
Factors Affecting ◽  
Chemical Shift Data ◽  
Shift Data ◽  
Insight Into

A 19F n.m.r. study shows that the β-cyclodextrin complexes of deprotonated α-(p- fluorophenyl ) glycine, N-acetyl-α-(p- fluorophenyl ) glycine , deprotonated N-acetyl-α-(p- fluorophenyl ) glycine , and N-(p- fluorobenzoyl ) valine are characterized by stability constants KR/dm3 mol-1 and Ks/dm3 mol-1 =13�2 and 21�3, 34�1 and 35�2, 12�1 and 12� 1, and 84�2 and 93�2, respectively, where the first and second of each pair of values refers to the complex formed by the R and S enantiomers of the fluorinated amino acid derivatives, respectively, in 10% aqueous D2O solution at 295.5 K and I = 0.10 mol dm-3. A comparison of these data and the associated 19F chemical shift data with those for the analogous α- and γ- cyclodextrin complexes provides an insight into the factors affecting the stabilities and structures of these complexes.

scholarly journals Ni/Photoredox-Catalyzed Enantioselective Cross-Electrophile Coupling of Styrene Oxides with Aryl Iodides

2021 ◽  
Author(s):  
Sii Hong Lau ◽  
Meredith Borden ◽  
Talia Steiman ◽  
Lucy Wang ◽  
Marvin Parasram ◽  
...  
Keyword(s):  
Linear Regression ◽  
Transition State ◽  
Cross Coupling ◽  
Reductive Coupling ◽  
Mechanistic Studies ◽  
State Structure ◽  
Transition State Structure ◽  
Aryl Iodides ◽  
Electronic Character ◽  
Insight Into

A Ni/photoredox-catalyzed enantioselective reductive coupling of styrene oxides and aryl iodides is reported. This reaction affords access to enantioenriched 2,2-diarylalcohols from racemic epoxides via a stereoconvergent mechanism. Multivariate linear regression (MVLR) analysis with 29 bioxazoline (BiOx) and biimidazoline (BiIm) ligands revealed that enantioselectivity correlates with electronic properties of the ligands, with more electron-donating ligands affording higher ee’s. Mechanistic studies were conducted, lending support to the hypothesis that the electronic character of the ligands influences the enantioselectivity by altering the position of the transition state structure along the reaction coordinate. This study demonstrates the benefits of utilizing statistical modeling as a platform for mechanistic understanding and provides new insight into an emerging class of chiral ligands for stereoconvergent Ni and Ni/photoredox cross-coupling.

Transition metal-free aerobic oxidative cleavage of the C–N bonds of α-amino esters

2019 ◽  
Vol 6 (23) ◽  
pp. 3854-3858
Author(s):  
Shenpeng Tan ◽  
Feng Li ◽  
Soojun Park ◽  
Sanghee Kim
Keyword(s):  
Amino Acid ◽  
Transition Metal ◽  
Metal Catalysts ◽  
Oxidative Cleavage ◽  
Amino Acid Derivatives ◽  
Metal Free ◽  
Amino Esters

A base-mediated aerobic oxidative cleavage of α-amino esters involving a hydroperoxide intermediate was reported, which represents the first example of the cleavage of the α-C–N bonds of amino acid derivatives without the aid of metal catalysts.

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