Results 51 to 60 of about 138,145 (310)

A Benchmark of Density Functional Approximations For Thermochemistry and Kinetics of Hydride Reductions of Cyclohexanones

open access: yesChemistryOpen, 2019
The performance of density functionals and wavefunction methods for describing the thermodynamics and kinetics of hydride reductions of 2‐substituted cyclohexanones has been evaluated for the first time.
Xavier Deraet   +5 more
doaj   +1 more source

Enantioselective PCCP Brønsted acid-catalyzed aza-Piancatelli rearrangement. [PDF]

open access: yes, 2019
An enantioselective aza-Piancatelli rearrangement has been developed using a chiral Brønsted acid based on pentacarboxycyclopentadiene (PCCP). This reaction provides rapid access to valuable chiral 4-amino-2-cyclopentenone building blocks from readily ...
Delgado, Jose M   +5 more
core  

A Concise Total Synthesis of (--)-Maoecrystal Z [PDF]

open access: yes, 2011
The first total synthesis of (--)-maoecrystal Z is described. The key steps of the synthesis include a diastereoselective Ti^(III)-mediated reductive epoxide coupling reaction and a diastereoselective Sm^(II)-mediated reductive cascade cyclization ...
Cha, Jacob Y.   +2 more
core   +2 more sources

Synthesis of Polysubstituted Tetrahydro‐1,4‐Thiazepines by Rhodium‐Catalyzed Ring Expansion of Dihydro‐1,3‐Thiazines with Diazoesters

open access: yesAdvanced Synthesis &Catalysis, EarlyView.
A rhodium(II)‐catalyzed ring expansion of stereodefined dihydro‐1,3‐thiazines with diazomalonates gives 1,4‐thiazepines via a sulfonium ylide rearrangement. The reaction shows a cis/trans reactivity divergence arising from different metal coordination, as revealed by experiments and density functional theory studies.
Laurine Tual   +3 more
wiley   +1 more source

Atroposelective Suzuki–Miyaura Coupling to Form 2‐Amino‐2′‐Hydroxybiphenyls Enabled by sRuPhos

open access: yesAngewandte Chemie, EarlyView.
We report a new chiral phosphine ligand, sRuPhos, which permits the highly enantioselective Suzuki–Miyaura coupling of ortho‐aniline and ortho‐phenol building blocks. This results in 2‐amino‐2′‐hydroxybiphenyls with very high enantiomeric excesses, products that will have application in pharmaceutical synthesis and ligand design for catalysis ...
Hamzah Sharif   +3 more
wiley   +2 more sources

Free radical 5-exo-dig cyclization as the key step in the synthesis of bis-butyrolactone natural products: experimental and theoretical studies [PDF]

open access: yes, 2011
Radical cyclization reactions were performed by 5-exo-dig mode to yield cis-fused bicyclic systems, leading to the synthesis of bis-butyrolactone class of natural products.
Allinger   +23 more
core   +1 more source

AI‐Driven Acceleration of Fluorescence Probe Discovery

open access: yesAdvanced Science, EarlyView.
We present PROBY, an AI model trained on large‐scale datasets to predict key photophysical properties and accelerate the discovery of target‐specific fluorescent probes. By screening a target‐annotated library, PROBY identifies candidate probes for diverse targets and could guide probe optimization, enabling a range of in vitro and in vivo imaging ...
Xuefeng Jiang   +18 more
wiley   +1 more source

Halide Bond Assisted Double Desymmetrization of Meso‐Dicarboxylic Acids with Symmetrical Olefins via Asymmetric Halogenation

open access: yesAngewandte Chemie, EarlyView.
This work demonstrates a double desymmetrization of meso‐dicarboxylic acids with symmetrical olefins, constructing complex chiral lactones with six stereocenters in one step. Unexpectedly, the halide bond was found to be crucial in achieving high stereoselectivity.
Qingyu Zhang   +3 more
wiley   +2 more sources

Highly Diastereo- and Enantioselective Allylboration of Aldehydes using alpha-Substituted Allyl/Crotyl Pinacol Boronic Esters via in Situ Generated Borinic Esters [PDF]

open access: yes, 2013
Readily available, alpha-substituted allyl/crotyl pinacol boronic esters often give low E/Z selectivity (with Z favored) in reactions with aldehydes. We found that addition of nBuLi to the pinacol boronic ester followed by trapping of the alkoxide with ...
Althaus M.   +60 more
core   +2 more sources

Halorotetin B, A Novel Terpenoid Compound Derived from Marine Ascidian, Suppresses Tumor Growth by Targeting the Cell Cycle Regulator UBE2C

open access: yesAdvanced Science, EarlyView.
Halorotetin B, a novel small‐molecule terpenoid identified from an edible marine ascidian, exhibits strong anti‐tumor activity both in vitro and in vivo through direct targeting UBE2C to induce tumor cell cycle arrest and then lead tumor cell senescence. As a newly discovered UBE2C inhibitor, Halorotetin B can serve as a novel potential cell senescence
Shanhao Han   +6 more
wiley   +1 more source

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