Results 41 to 50 of about 511,953 (205)

Axially Chiral Nonalternant Polycyclic Aromatic Hydrocarbon With Consecutive Pentagons Exhibiting Large Spin‐Polarized Current

Angewandte Chemie, EarlyView.
Here we report two nonalternant polycyclic aromatic hydrocarbons (PAH) (1 and 2), which contain two and four consecutive pentagons, respectively. Under acidic conditions, 1 and 2 dimerize to afford the axially chiral dimers AC1 and AC2. The central azulene moiety in both 2 and AC2 shows an unusually short transannular bond of 1.366 Å.
Chang Wang, Jiaxin Luo, Haipeng Lu, Junzhi Liu   +3 more
wiley   +2 more sources

Assignment-free chirality detection in unknown samples via microwave three-wave mixing

Communications Chemistry, 2022
Identification of chiral molecules in multi-component mixtures of unknown compositions remains a challenge. Here, the authors show that microwave three-wave mixing that uses broad-spectrum fields can detect chiral molecules in enantiomeric excess without
Greta Koumarianou, Irene Wang, Lincoln Satterthwaite, David Patterson   +3 more
doaj   +1 more source

Cobalt‐Catalyzed Asymmetric Construction of Boron Stereocenters With C–N Axial Chirality

Advanced Science, EarlyView.
A cobalt/Salox‐catalyzed one‐pot annulation enables enantioselective formation of B‐stereogenic centers and C─N axial chirality via C─H/N─H annulation, affording diverse fluorescent products with high stereocontrol and optoelectronic potential. ABSTRACT The efficient construction of boron stereogenic centers alongside axial chirality remains a ...
Subramani Kumaran, Harihara Subramanian Ravi Sankar, Pritam Maity, J. Richard Premkumar, Abir Das, Basker Sundararaju   +5 more
wiley   +1 more source

1,3‐Brook Rearrangement of α‐Silyl Allylic Alcohols: Copper‐Catalyzed Enantiospecific Formation of Allenes and Copper‐Mediated ipso‐Substitution Reactions Affording Trisubstituted Alkenes

Angewandte Chemie, EarlyView.
A regioselective ruthenium catalyzed trans‐hydrosilylation of propargyl alcohols followed by a 1,3‐Brook rearrangement opens access to reactive organocopper intermediates, which evolve upon warming into allenes with strict chirality transfer to the emerging axis; alternatively, these reactive species can be trapped with a large variety of electrophiles
Jack L. Sutro, Felix Anderl, Paul Haf‐Moths, Alois Fürstner   +3 more
wiley   +2 more sources

Estimation of Enantiomeric Excess Based on Rapid Host–Guest Exchange

Chemosensors, 2021
Chiral molecules possess enantiomers that have non-superimposable chemical structures but exhibit identical nuclear magnetic resonance (NMR) spectra.
Jan Labuta, Shinsuke Ishihara, Daniel T. Payne, Kazuyoshi Takimoto, Hisako Sato, Lenka Hanyková, Katsuhiko Ariga, Jonathan P. Hill   +7 more
doaj   +1 more source

Assessing the Use of 50% Enantiomeric Excess Bupivacaine-Loaded Microspheres after Sciatic Nerve Block in Rats [PDF]

, 2011
SummaryBackground and objectivesTo achieve better therapeutic benefits of local anesthetics in the control of postoperative pain through controlled-release carrier.
Tenorio, Sergio Bernardo, Tanaka, Pedro Paulo, de Oliveira, Rohnelt Machado   +2 more
core   +1 more source

NiH‐Catalyzed Enantio‐ and Regioselective Hydroselenylation of Unactivated Alkenes

Advanced Science, EarlyView.
Nickel‐hydride‐catalyzed enantio‐ and regioselective hydroselenylation of unactivated alkenes provides access to chiral organoselenium compounds. Enantiodetermining Ni–H insertion followed by single‐electron diselenide activation generates selenyl radical.
Hyung‐Joon Kang, Jaehun Kim, Sungwoo Hong   +2 more
wiley   +1 more source

Record Dissymmetry in Vibrational Optical Activity: Combining Vibronic Coupling and Aggregation in Cobalt(II) Camphorate Complexes

Angewandte Chemie, EarlyView.
The cobalt(II) bis(trifluoroacetylcamphorate) scaffold exhibits versatile coordination chemistry with solvent‐driven ligand exchange and geometrical rearrangements, associated with unique chiroptical properties. Microcrystalline suspension of [Co(tfc)2(CH3CN)2] revealed the largest VCD dissymmetry factor ever reported (g ≈ 0.2 at 1600 cm−1), arising ...
Gianmarco Papi, Massimo Guelfi, Stefano Zacchini, Fabio Marchetti, Gennaro Pescitelli   +4 more
wiley   +2 more sources

Chiroptical activity of hydroxycarboxylic acids with implications for the origin of biological homochirality

Communications Chemistry, 2021
Enantiomerically-enriched hydroxycarboxylic acids have been found in meteorites, but the possible origin of this asymmetry has not been explored experimentally.
Jana Bocková, Nykola C. Jones, Uwe J. Meierhenrich, Søren V. Hoffmann, Cornelia Meinert   +4 more
doaj   +1 more source

Enantioselective Access to Trifluoromethylated Spirocyclopropyl Heterocycles

Advanced Science, EarlyView.
We report a rhodium‐catalyzed asymmetric [2+1] spirocyclopropanation of methylene azacycles with trifluoromethyl carbenes in situ derived from fluoroalkyl triftosylhydrazones. ABSTRACT Chiral spirocyclopropyl heterocycles have emerged as privileged three‐dimensional structural motifs in medicinal chemistry.
Yuanhao Zhu, Youzhi Xu, Weitao Zhang, Yongyue Ning, Yaojia Jiang, Yongquan Ning, Genping Huang, Jiawei Cheng, Paramasivam Sivaguru, Xihe Bi   +9 more
wiley   +1 more source