Results 71 to 80 of about 1,601,441 (195)

Rhodium‐Catalyzed Synthesis of Enantioenriched α‐Substituted Primary Amines Through Asymmetric Transfer Hydrogenation

open access: yesChemistry – A European Journal, EarlyView.
Enantioenriched α‐substituted primary amines are efficiently prepared by rhodium‐catalyzed asymmetric transfer hydrogenation of ortho‐hydroxyaryl N─H imines under mild conditions using a low catalyst loading and ammonium formate as the hydrogen source in high yields (up to 99%) and enantioselectivities (up to 99% ee).
Chonghuo Liu   +4 more
wiley   +1 more source

Polar stationary phases for capillary electrochromatography

open access: yes, 2004
This review article summarizes the variety of polar stationary phases that have been employed for capillary electrochromatographic separations. Compared with reversed-phase stationary phases, the polar alternatives provide a completely different ...
Zou, HF, Xie, CH, Hu, JW, Fu, HJ
core   +1 more source

Exploring the Boundaries of Aromaticity in Complex Structures and Excited States Through Computational Analysis

open access: yesChemistry – A European Journal, EarlyView.
Understanding aromaticity has evolved from benzene‐centric concepts to a broad multidimensional framework spanning organic, inorganic, and excited‐state systems. This review highlights ambiguities between magnetic, electronic, geometric, and energetic descriptors, emphasizing the need for unified, multi‐criteria approaches.
Sílvia Escayola   +2 more
wiley   +1 more source

Synthesis of covalently bonded cellulose derivative chiral stationary phases with a bifunctional reagent of 3-(triethoxysilyl)propyl isocyanate

open access: yes, 2003
A bifunctional reagent of 3-(triethoxysilyl)propyl isocyanate (TEPI) was initially adopted as a spacer reagent to prepare the bonded types of chiral stationary phases (CSPs) with cellulose derivatives.
Kong, L   +4 more
core   +1 more source

Generalized Beth–Uhlenbeck Entropy Formula From the Φ‐Derivable Approach

open access: yesContributions to Plasma Physics, EarlyView.
ABSTRACT We derive a generalized Beth–Uhlenbeck formula for the entropy of a dense fermion system with strong two‐particle correlations, including scattering states and bound states. We work within the Φ‐derivable approach to the thermodynamic potential.
David Blaschke, Gerd Röpke, Gordon Baym
wiley   +1 more source

Next‐Generation Carbon‐Based Anodes for Alkali Metal‐Ion Batteries: Recent Progress on Biphenylene and Emerging Materials

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Recent advances in carbon‐based anodes for alkali metal‐ion batteries are critically reviewed, with emphasis on biphenylene and other emerging carbon allotropes. Biphenylene exhibits exceptional theoretical electrochemical properties beyond conventional graphite, highlighting its strong potential as a next‐generation anode material once scalable ...
Adewale Hammed Pasanaje, Nirpendra Singh
wiley   +1 more source

Competing Charge Transport Pathways: A Spirobifluorene‐Based Molecular Loop

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
A rigid molecular loop integrating a spirobifluorene (SBF) core with a cycloparaphenylene (CPP) moiety provides two distinct transport channels. Through‐space spiroconjugation and radial π‐conjugation along a CPP backbone coexist within a single molecule.
Brian Ogi   +4 more
wiley   +1 more source

Resolution Approaches Toward Enantiopure Planar Chiral 7‐bromo‐4‐hydroxy [2.2]paracyclophane

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
This work describes access to both enantiomers of planar chiral 7‐bromo‐4‐hydroxy [2.2]paracyclophane through direct resolution of the racemate using an L‐isoleucine‐derived chiral auxiliary or through resolution of 4‐hydroxy [2.2]paracyclophane, followed by regioselective bromination.
Arthur Le Coz   +5 more
wiley   +1 more source

A General Stereochemical Model for Grignard Additions to α‐Alkoxy Nitrones: Density Functional Theory Evidence for an Intrinsic α‐Chelation‐Controlled Pathway

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
A comprehensive DFT conformational study of Grignard additions to α‐alkoxy nitrones reveals that the reaction proceeds through a dinuclear α‐chelated transition structure in which the nitrone oxygen coordinates two magnesium centers. Other common additives, such as zinc dichloride, boron trifluoride, and dimethylaluminum chloride, were also studied ...
Manuel Pedrón   +2 more
wiley   +1 more source

Enantioselective Chromatography: an Essential and Versatile Tool for the Analytical and Preparative Separation of Enantiomers

open access: yesCHIMIA, 1997
Chromatography on chiral stationary phases and electrophoresis in the presence of chiral selectors have become essential tools for the determination of enantiomeric purity in connection with synthesis and with biological studies of chiral ...
Eric R. Francotte
doaj   +2 more sources

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