Role of Encapsulated Metal Cation in the Reactivity and Regioselectivity of the C60 Diels–Alder Reaction

2015 ◽  
Vol 119 (12) ◽  
pp. 3098-3106 ◽  
Author(s):  
Cheng-Xing Cui ◽  
Ya-Jun Liu
Keyword(s):  
Metal Cation ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

ChemInform Abstract: Switched Role of Fullerene in the Diels-Alder Reaction: Facile Addition of Dienophiles to the Conjugated Fullerene Diene Moiety.

ChemInform ◽  
2009 ◽  
Vol 40 (24) ◽  
Author(s):  
Jiayao Yao ◽  
Zuo Xiao ◽  
Jianxin Zhang ◽  
Xiaobing Yang ◽  
Liangbing Gan ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

ChemInform Abstract: Highly Diastereoselective Diels-Alder Reaction Mediated by a Chiral Auxiliary Derived from Amino Indanol: The Role of Conformation on Diastereoselectivity.

ChemInform ◽  
2010 ◽  
Vol 27 (5) ◽  
pp. no-no
Author(s):  
I. W. DAVIES ◽  
C. H. SENANAYAKE ◽  
L. CASTONGUAY ◽  
R. D. LARSEN ◽  
T. R. VERHOEVEN ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Chiral Auxiliary ◽  
Diels Alder Reaction

scholarly journals On the Role of Hydrogen Bond Strength and Charge Transfer of a Diels-Alder Reaction On-Water: Semiempirical and Free Energy Calculations.

2021 ◽  
Author(s):  
Andrés Henao Aristizàbal ◽  
Yomna Gohar ◽  
René Whilhelm ◽  
Thomas D. Kühne
Keyword(s):  
Hydrogen Bond ◽  
Free Energy ◽  
Charge Transfer ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Alder Reaction ◽  
Free Energy Calculations ◽  
Diels Alder ◽  
Diels Alder Reaction

Accelerated chemistry at the interface with water has received increasing attention. The mechanisms behind the enhanced reactivity On-Water are not yet clear. In this work we use a Langevin scheme in the spirit of second generation Car-Parrinello to accelerate the second-order density functional Tight-Binding (DFTB2) method in order to investigate the free energy of two Diels-Alder reaction On-Water: the cycloaddition between cyclopentadiene and ethyl cinnamate or thionocinnamate. The only difference between the reactants is the substitution of a carbonyl oxygen for a thiocarbonyl sulfur, making possible the distinction between them as strong and weak hydrogen-bond acceptors. We find a different mechanism for the reaction during the transition states and uncover the role of hydrogen bonds along with the reaction path. Our results suggest that acceleration of Diels-Alder reactions do not arise from an increased number of hydrogen bonds at the transition state and charge transfer plays a significant role. However, the presence of water and hydrogen-bonds is determinant for the catalysis of these reactions.

Highly diastereoselective diels-alder reaction mediated by a chiral auxiliary derived from amino indanol: The role of conformation on diastereoselectivity

1995 ◽  
Vol 36 (42) ◽  
pp. 7619-7622 ◽  
Author(s):  
Ian W. Davies ◽  
Chris H. Senanayake ◽  
Laurie Castonguay ◽  
Robert D. Larsen ◽  
Thomas R. Verhoeven ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Chiral Auxiliary ◽  
Diels Alder Reaction

scholarly journals The Role of Iodine Catalyst in the Synthesis of 22-Carbon Tricarboxylic Acid and Its Ester: A Case Study

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 972
Author(s):  
Liu ◽  
Zhang ◽  
Wang ◽  
Zan ◽  
Zhang
Keyword(s):  
Energy Gap ◽  
Tricarboxylic Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Proton Nuclear Magnetic Resonance ◽  
Ionization Mass ◽  
Double Bonds ◽  
Chemical Structures ◽  
Diels Alder Reaction

Here, 22-carbon tricarboxylic acid (C22TA) and its ester (C22TAE) were prepared via the Diels–Alder reaction of polyunsaturated fatty acids (PUFAs) and their esters (PUFAEs) as dienes with fumaric acid (FA) and dimethyl fumarate (DF) as dienophiles, respectively. The role of an iodine catalyst for the synthesis of C22TA and C22TAE in the Diels–Alder type reaction was investigated using a spectroscopic approach. The chemical structures of the products were characterized using proton nuclear magnetic resonance (1H-NMR) and electrospray ionization mass spectrometry (ESI-MS) analysis. Results showed that nonconjugated dienes can react with dienophiles through a Diels–Alder reaction with an iodine catalyst, and that iodine transformed the nonconjugated double bonds of dienes into conjugated double bonds via a radical process. DF was more favorable for the Diels–Alder reaction than FA. This was mainly because the dienophile DF contained an electron-withdrawing substituent, which reduced the highest and lowest occupied molecular orbital (HOMO–LUMO) energy gap and accelerated the Diels–Alder reaction. By transforming nonconjugated double bonds into conjugated double bonds, iodine as a Lewis acid increased the electron-withdrawing effect of the carbonyl group on the carbon–carbon double bond and reduced the energy difference between the HOMO of diene and the LUMO of dienophile, thus facilitating the Diels–Alder reaction.

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