The Diels–Alder reaction of C60 and cyclopentadiene in mesoporous silica as a reaction medium

2011 ◽  
Vol 47 (22) ◽  
pp. 6338 ◽  
Author(s):  
Satoshi Minakata ◽  
Toshiki Nagamachi ◽  
Kazuhisa Nakayama ◽  
Takeyuki Suzuki ◽  
Takanori Tanaka
Keyword(s):  
Mesoporous Silica ◽  
Reaction Medium ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

ChemInform Abstract: The Diels-Alder Reaction of C60 and Cyclopentadiene in Mesoporous Silica as a Reaction Medium.

ChemInform ◽  
2011 ◽  
Vol 42 (34) ◽  
pp. no-no
Author(s):  
Satoshi Minakata ◽  
Toshiki Nagamachi ◽  
Kazuhisa Nakayama ◽  
Takeyuki Suzuki ◽  
Takanori Tanaka
Keyword(s):  
Mesoporous Silica ◽  
Reaction Medium ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

scholarly journals A molecular nanocap activated by superparamagnetic heating for externally stimulated cargo release

2016 ◽  
Vol 52 (9) ◽  
pp. 1843-1846 ◽  
Author(s):  
B. Rühle ◽  
S. Datz ◽  
C. Argyo ◽  
T. Bein ◽  
J. I. Zink
Keyword(s):  
Iron Oxide ◽  
Mesoporous Silica ◽  
Superparamagnetic Iron Oxide ◽  
Alder Reaction ◽  
Silica Shell ◽  
Diels Alder ◽  
Shell Nanoparticles ◽  
Diels Alder Reaction ◽  
Iron Oxide Core

A novel thermoresponsive snaptop for stimulated cargo release from superparamagnetic iron oxide core – mesoporous silica shell nanoparticles based on a [2 + 4] cycloreversion reaction (retro-Diels Alder reaction) is presented.

scholarly journals Accurate Diels-Alder Energies and Endo Selectivity in Ionic Liquids Using the OPLS-VSIL Force Field

2020 ◽  
Vol 21 (4) ◽  
pp. 1190 ◽  
Author(s):  
Caroline Velez ◽  
Brian Doherty ◽  
Orlando Acevedo
Keyword(s):  
Free Energy ◽  
Ionic Liquid ◽  
Hydrogen Bonding ◽  
Ionic Liquids ◽  
Transition State ◽  
Force Field ◽  
Reaction Medium ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

Our recently developed optimized potentials for liquid simulations-virtual site ionic liquid (OPLS-VSIL) force field has been shown to provide accurate bulk phase properties and local ion-ion interactions for a wide variety of imidazolium-based ionic liquids. The force field features a virtual site that offloads negative charge to inside the plane of the ring with careful attention given to hydrogen bonding interactions. In this study, the Diels-Alder reaction between cyclopentadiene and methyl acrylate was computationally investigated in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6], as a basis for the validation of the OPLS-VSIL to properly reproduce a reaction medium environment. Mixed ab initio quantum mechanics and molecular mechanics (QM/MM) calculations coupled to free energy perturbation and Monte Carlo sampling (FEP/MC) that utilized M06-2X/6-31G(d) and OPLS-VSIL gave activation free energy barriers of 14.9 and 16.0 kcal/mol for the endo-cis and exo-cis Diels-Alder reaction pathways, respectively (exptl. ΔH‡ of 14.6 kcal/mol). The endo selectivity trend was correctly predicted with a calculated 73% endo preference. The rate and selectivity enhancements present in the endo conformation were found to arise from preferential hydrogen bonding with the exposed C4 ring hydrogen on the BMIM cation. Weaker electronic stabilization of the exo transition state was predicted. For comparison, our earlier ±0.8 charge-scaled OPLS-2009IL force field also yielded a ΔG‡ of 14.9 kcal/mol for the favorable endo reaction pathway but did not adequately capture the highly organized solvent interactions present between the cation and Diels-Alder transition state.

The Diels-Alder Reaction of 2-Ethenyl-1,4-Benzodioxin: A New and Simple Synthesis of Bisaryl Ethers

Synlett ◽  
1989 ◽  
Vol 1989 (01) ◽  
pp. 30-32
Author(s):  
Thomas V. Lee ◽  
Alistair J. Leigh ◽  
Christopher B. Chapleo
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Simple Synthesis ◽  
Diels Alder Reaction

The intermolecular anthracene-transfer in a regiospecific antipodal C60 difunctionalization

2020 ◽  
Author(s):  
Radu Talmazan ◽  
Klaus R. Liedl ◽  
Bernhard Kräutler ◽  
Maren Podewitz
Keyword(s):  
Noncovalent Interactions ◽  
Interaction Model ◽  
Alder Reaction ◽  
Diels Alder ◽  
Stacking Interactions ◽  
Pi Stacking ◽  
Diels Alder Reaction ◽  
Double Decker ◽  
Anthracene Molecule ◽  
New Strategies

We analyze the mechanism of the topochemically controlled difunctionalization of C60 and anthracene, where an anthracene molecule is transferred from one C60 monoadduct to another one under exclusive formation of equal amounts of C60 and the difficult to make antipodal C60 bisadduct. Our herein disclosed dispersion corrected DFT studies show the anthracene transfer to take place in a synchronous retro Diels-Alder/Diels-Alder reaction: an anthracene molecule dissociates from one fullerene under formation of an intermediate, while already undergoing stabilizing interactions with both neighboring fullerenes, facilitating the reaction kinetically. In the intermediate, a planar anthracene molecule is sandwiched between two neighboring fullerenes and forms equally strong "double-decker" type pi-pi stacking interactions with both of these fullerenes. Analysis with the distorsion interaction model shows that the anthracene unit of the intermediate is almost planar with minimal distorsions. This analysis sheds light on the existence of noncovalent interactions engaging both faces of a planar polyunsaturated ring and two convex fullerene surfaces in an unprecedented 'inverted sandwich' structure. Hence, it sheds light on new strategies to design functional fullerene based materials.<br>

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