Results 81 to 90 of about 32,089 (279)

Improved enantioselectivity of a lipase by rational protein engineering

, 2001
A model based on two different binding modes for alcohol enantiomers in the active site of a lipase allowed rational redesign of its enantioselectivity, 1-Halo-2-octanols were poorly resolved by Candida antarctica lipase B.
Rotticci, D., Hult, Karl,, Norin, T., Rotticci-Mulder, J. C., Denman, S.   +4 more
core   +1 more source

Bond Energy Descriptors Enable Machine Learning With Limited Data: Design of Capping Agents for Thermoplastic Polyurethane Recycling

Advanced Intelligent Discovery, EarlyView.
Data scarcity is a critical bottleneck for machine learning in applied chemistry. We show that physics‐informed descriptors enable a simple linear model to predict the deblocking temperatures of capped diisocyanates to within 11 °C from just 19 measurements, demonstrating that embedding physical insight into descriptors, rather than relying on ...
Remsha Rafiq, Barbaro Zulueta, Hannah Zucco, Ramakrishna Suresh, Jason E. Shoemaker, Michael Call, Daylan Sheppard, Glenn Cormack, John A. Keith, Götz Veser   +9 more
wiley   +1 more source

Control of Helix Screw‐Sense Preference in Dynamic Foldamers of meso Symmetry Built From Chiral Monomeric Units

Angewandte Chemie, EarlyView.
Sequence‐diverse meso and “near‐meso” oligourea foldamers are reported and exhibit stimulus‐responsive helix screw‐sense control governed by terminal‐group desymmetrization and sequence‐encoded helix stability. ABSTRACT Meso oligoureas are dynamic hydrogen‐bonded foldamers capable of reversible helix polarity inversion but have so far been limited to ...
Naveen Gupta, Mégane Bornerie, Bo Li, Antoine Hacihasanoglu, Orlando Villegas Bello, Stéphanie Antunes, Estelle Morvan, Jean‐Marc Sotiropoulos, Philippe Carbonnière, Morgane Pasco, Brice Kauffmann, Céline Douat, Sung Hyun Yoo, Gilles Guichard   +13 more
wiley   +2 more sources

Atroposelective Pd(0)‐Catalyzed Direct Intermolecular C─H Arylation of Thiazole N‐Oxides Provides Access to Heterobiaryls

Angewandte Chemie, EarlyView.
An enantioselective Pd(0)‐catalysed arylation at the C4‐position of thiazole N‐oxides directly forges the atropochiral heterobiaryl axis. A tailored point‐ and axially chiral monodentate phosphine ensures high reactivities along with a tight stereocontrol.
Vitalii Smal, Nicolai Cramer
wiley   +2 more sources

Extending El Sayed's Rule by 1(n,π*)–3(n,π*) Rotation via Intramolecular Secondary Interaction Enables Room‐Temperature Circularly Polarized Phosphorescence in Solution

Angewandte Chemie, EarlyView.
Weak but skilled: Our results highlight the crucial role of intramolecular secondary interactions to induce an efficient ISC between formally identical 1(n,π*) and 3(n,π*) states in chiral thionated phthalimide derivatives. This unprecedented type of inter‐system crossing (ISC) extends the usual thinking of the El‐Sayed principle and enables the ...
Oscar Charpentier, Marie Guesdon, Catherine Demangeat, Maher Hojorat, Joseph Young, Emrys W. Evans, Vincent Dorcet, Nicolas Galland, Denis Jacquemin, Ludovic Favereau   +9 more
wiley   +2 more sources

Z‐Retentive Enantioselective Rh‐Catalyzed Hydroarylation of E,Z‐Dienes

Angewandte Chemie, EarlyView.
The Rh‐catalyzed hydroarylation of conjugated E,Z‐dienoates is found to proceed with high selectivity for addition to the E‐alkene unit. Mechanistic analysis of this Z‐retentive process points towards preferred binding of the E‐alkene unit to a Rh‐aryl species to give rise to the observed selectivity and that Rh‐enolate protonolysis to be turnover ...
Wesley McNutt, Hima Kozhummal, Abdullah Al‐Mashqbeh, Alex Brown, Rylan J. Lundgren   +4 more
wiley   +2 more sources

On Serine Octamer Substitution Reactions. [PDF]

Rapid Commun Mass Spectrom
ABSTRACT Rationale Monomeric amino acids substitute into the ionized serine octamer (Ser8), a magic number cluster that exhibits chiral behavior. Small biomolecules, such as amino acids (AA), substitute into the octamer enantioselectively, giving Ser7AAH+ and Ser6AA2H+ favoring clusters of all L‐ or all D‐chirality.
Shira BA, Thomas AKE, Cooks RG.
europepmc   +2 more sources

Chiroptical Switching by Stereoselective Photochemical Sigmatropic Rearrangements: Experimental Realization of Calderoselectivity

Angewandte Chemie, EarlyView.
Calderoselectivity is established as a stereochemical principle for sigmatropic rearrangements. A homoannulene‐based chiroptical photoswitch undergoes a photochemical [1,11] sigmatropic rearrangement with control of the acyl movement on top of the cyclic π system.
Anne Krenkel, Frederike Beyer, Malte Feßner, Trung Tran Ngoc, Tobias Rüffer, Dominik Hornig, Martin Breugst, Christian Merten, Johannes F. Teichert   +8 more
wiley   +2 more sources

Enantioselectivity by Mass Spectrometry

, 2002
A review. Understanding the detailed mechanism of transfer of chiral information between mols. in living systems and in supramol. assemblies requires the quantification of the intrinsic short-range forces controlling enantioselectivity in simplified ...
SPERANZA, Maurizio, Maurizio Speranza
core   +1 more source

Enantioselective Aminosilylation of Alkenes by Palladium/Ming‐Phos‐Catalyzed Tandem Narasaka–Heck/Silylation Reaction

Advanced Science
A Pd‐catalyzed enantioselective aminosilylation of alkenes via tandem Aza‐Heck/silylation reaction under Pd/Sadphos catalysis is disclosed. A wide array of oxime esters and silicon reagents are tolerated, furnishing the chiral pyrrolines bearing one ...
Kangning Cao, Jie Han, Wenshao Ye, Dejun Hu, Zihao Ye, Junfeng Yang, Junliang Zhang, Fener Chen   +7 more
doaj   +1 more source