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

Irreversible endo-Selective Diels–Alder Reactions of Substituted Alkoxyfurans: A General Synthesis of endo-Cantharimides

The [4+2] cycloaddition of 3-alkoxyfurans with N-substituted maleimides provides the first general route for preparing endo-cantharimides. Unlike the corresponding reaction with 3H furans, the reaction can tolerate a broad range of 2-substitued furans including alkyl, aromatic, and heteroaromatic groups. The cycloaddition products were converted into a range of cantharimide products with promis...

JCE0597 p582 endo- and exo-Stereochemistry in the Diels-Alder Reaction: Kinetic versus Thermodynamic Control

In these experiments, which were used in the problemsolving mode (1), the stereoselectivity of the Diels–Alder cycloaddition of N-phenylmaleimide to furan is deduced by the characteristic splitting patterns in the proton-NMR spectra. The relationship of coupling constants to dihedral angle, as described by the Karplus equation, is illustrated. The data can also be used to demonstrate the concep...

Interactions between Organic Compounds and Ionic Liquids. Selectivity and Capacity Characteristics of Ionic Liquids

Optimization of the OPLS-AA Force Field for Long Hydrocarbons.

The all-atom optimized potentials for liquid simulations (OPLS-AA) force field is a popular force field for simulating biomolecules. However, the current OPLS parameters for hydrocarbons developed using short alkanes cannot reproduce the liquid properties of long alkanes in molecular dynamics simulations. Therefore, the extension of OPLS-AA to (phospho)lipid molecules required for the study of ...

Atomic force microscopy in viscous ionic liquids.

Extracting quantitative information from amplitude-modulation atomic force microscopy (AM-AFM) in viscous ionic liquids is difficult because existing theory requires knowledge of the cantilever natural frequency, which cannot be measured in the absence of a resonance peak. We present a new model that describes cantilever dynamics in an overdamped medium (Q < 0.5) and derive the theory necessary...