Results 61 to 70 of about 363,660 (280)

Origin of Enantioreversal in the Rhodium-Catalyzed Asymmetric Hydrogenation of Prochiral Enamides and the Effect of the α-Substituent

, 2016
The enantioselectivity of prochiral enamide hydrogenation depends on the structure of the enamide, with particular sensitivity to the nature of the α-substituent. Recently, Burk has reported a spectacular example of structure sensitivity for [Rh(DuPHOS)]+
Steven Feldgus (2401402), Clark R. Landis (1486096)   +1 more
core   +3 more sources

13C NMR spectra and substituent effects of meta and para substituted benzoyl isothiocyanates

, 1985
13C NMR spectra have been studied of 20 meta and para substituted benzoyl isothiocyanates and corresponding benzoyl chlorides. The 13C SCS values of the carbon atom in NCS group have been found to correlate linearly with the Hammet σm,p constants of the ...
Ivan Danihel, Pavol Kristian, Dušan Košťík, Ján Imrich, Gabriela Barančíková   +4 more
core   +1 more source

Sticker Valence Governs Chain Collapse and Liquid‐Liquid Phase Separation in Peptide‐Inspired Associative Polymers

Advanced Science, EarlyView.
Peptide‐inspired associative polymers with arginine‐like guanidinium stickers and lysine‐like ammonium spacers undergo chain collapse and liquid‐liquid phase separation induced by reversible sticker associations. Sticker valence and tunable association strength jointly control the phase behavior, chain conformation, and interfacial cohesion of these ...
Seung‐Hwan Oh, Jinhoon Lee, Seunghyun Lee, Raehyun Jung, Sangyeop Lee, Su‐Mi Hur, Dong Woog Lee, Soo‐Hyung Choi   +7 more
wiley   +1 more source

Effect of Substituent on Ionisation of Saturated Fatty Acids

, 1964
The length of tho carbon chain of a fatty acid molecule has been found to have little effect on the ioniea­tion of the unsubstituted acid. Decided changes in pK values are observed when a substituent is introduced into the moleclue.
S. C. Rakshit and S. Guha
core   +1 more source

Printable Piezoresistive Hybrid Hydrogels Based on 2D MoS2 for Flexible Pulse Sensing

Advanced Science, EarlyView.
Hybrid 1T‐MoS2‐based hydrogels are engineered through UV curing and 3D printing to achieve tunable electromechanical properties for wearable sensing. These soft architectures enhance mechanical stability and reproducible piezoresistive responses within the physiological pressure range.
Jenny Flores, Arianna Bertero, Luca Ceseracciu, Daniel Jiménez‐Boland, Sara Domenici, Mattia Bramini, Paola Sánchez‐Moreno, Erica Scarcelli, Domenico Galdiero, Pavel Fedorov, Daniil Karnaushenko, Rossella Sesia, Ignazio Roppolo, Micaela Pozzati, Mattia Spedicati, Nicolò Petrini, Marco Sangermano, Bartolomeo Coppola, Teresa Gatti   +18 more
wiley   +1 more source

Toward Material‐Specific Peptides From in Silico Guided Peptide Engineering to Target PET in the Presence of PS

Advanced Science, EarlyView.
This work presents a computational–experimental strategy to engineer material‐binding peptides toward polymer specificity. Molecular dynamics simulations identified residues driving polystyrene binding, enabling targeted substitutions that greatly reduced polystyrene affinity while preserving PET binding.
Julian Luka, Marian Bienstein, Jonas Berger, Ulrich Schwaneberg   +3 more
wiley   +1 more source

A Theoretical Study of the Relationship between the Electrophilicity ω Index and Hammett Constant σp in [3+2] Cycloaddition Reactions of Aryl Azide/Alkyne Derivatives

Molecules, 2016
The relationship between the electrophilicity ω index and the Hammett constant σp has been studied for the [2+3] cycloaddition reactions of a series of para-substituted phenyl azides towards para-substituted phenyl alkynes. The electrophilicity ω index—a
Hicham Ben El Ayouchia, Hafid Anane, Moulay Lahcen El Idrissi Moubtassim, Luis R. Domingo, Miguel Julve, Salah-Eddine Stiriba   +5 more
doaj   +1 more source

Dual Nickel/Photoredox‐Catalyzed Regio‐ and Enantioselective Alkenylation of Epoxides

Advanced Science, EarlyView.
Ni/photoredox‐catalyzed stereoconvergent cross‐electrophile coupling of racemic epoxides with alkenyl bromides is described, affording β‐alkenyl products with up to 95% ee, excellent E‐selectivity, and complete regiocontrol. These versatile intermediates enable diverse chiral synthons; mechanistic studies suggest a halide ring‐opening followed by ...
Hongyan Lan, Shengzhou Jin, Zhao‐Dong Xu, Guigen Li, Dingyi Wang   +4 more
wiley   +1 more source

Synthesis, IR and NMR spectral correlations in some symmetrical diimines

Bulletin of the Chemical Society of Ethiopia, 2014
A series of diimines have been synthesized by coupling of diamine with substituted benzaldehydes. The purities of these diimines were checked by their analytical and spectroscopic data. The spectral frequencies νCN (cm-1), NMR chemical shifts (δ, ppm) of
G. Thirunarayanan
doaj   +1 more source

NMR characterization of substituent effects in cation–π interactions

, 2012
Substituent effects in C6H5X…M+ (M+ = Li+, Na+, K+, and ) systems have been characterized using isotropic nuclear magnetic shielding constants (σ). Good linear relationship between σ and the Hammett substituent constant σp is established which suggests ...
Suresh, Cherumuttathu H., Cherumuttathu H. Suresh, Fareed Bhasha Sayyed, Sayyed, Fareed Bhasha   +3 more
core   +1 more source