Results 71 to 80 of about 13,728 (257)

THE STEREOCHEMISTRY AND CONFORMATION OF LIGNIN AS JUDGED BY X-RAY CRYSTALLOGRAPHIC INVESTIGATIONS OF LIGNIN MODEL COMPOUNDS: ARYLGLYCEROL BETA-GUAIACYL ETHERS

BioResources, 2007
The conformations of a variety of crystalline lignin models representing different diastereomeric forms of structural elements in lignin of the arylglycerol -guaiacyl ether type have been studied using X-ray crystallography.
Jim Parkås, Knut Lundquist, Vratislav Langer   +2 more
doaj  

Comparative Study Related to Cardiovascular Safety between Bupivacaine (S75-R25) and Ropivacaine in Brachial Plexus Block

Brazilian Journal of Anesthesiology, 2013
Background and objectives Bupivacaine is a first choice for regional anesthesia considering its effectiveness, long duration and less motor blockade.
Adilson Hamaji, Marcelo Rosa de Rezende, Rames Mattar, Jr., Joaquim Edson Vieira, José Otávio Costa Auler, Jr.   +4 more
doaj   +1 more source

Catalytic Generation of Cationic Gold Carbene Complexes From 7‐Alkynylnorbornadienes and Their Intermolecular Cyclopropanation With Alkenes

Chemistry – A European Journal, EarlyView.
Efficient cationic gold(I)‐catalyzed intermolecular cyclopropanation of 7‐alkynylnorbornadiene derivatives has been developed. This methodology offers the synthesis of a new class of norbornene derivatives in high yield with excellent diastereoselectivity.
Kento Ishida, Kenta Toei, Fumiaki Tomi, Norio Sakai   +3 more
wiley   +1 more source

A Bio‐Based Chiroptical Overcrowded Alkene From Flavanone: Photoreactivity and Theoretical Investigation

Chemistry – A European Journal, EarlyView.
A sustainable route to photoresponsive molecular systems is achieved using the bio‐based flavanone (‐)‐isolonchocarpin from Tephrosia vogelii. Through McMurry homocoupling and light‐driven 6‐π‐electrocyclization, an overcrowded alkene and a fluorescent O‐heterocyclic phenanthrene are synthesized.
Deryl H. Limawan, Adrien Combe, Anthony Bongso, Bayu Dwiputra, Atthar L. Ivansyah, Roza R. Weber, Charlotte N. Stindt, Robby Roswanda, Ben L. Feringa   +8 more
wiley   +1 more source

Stereoretentive Nucleophilic Aromatic Substitution Accesses Atropisomeric 4‐Amino‐N‐Arylquinolinium Salts

Chemistry – A European Journal, EarlyView.
Quinolin‐4‐ones were converted to chloroquinolinium salts, allowing formation of axially chiral aminoquinolinium salts via an enantioretentive SNAr reaction with a variety of amine nucleophiles. The salts have a high rotational barrier, with a racemization half‐life of ∼1000s of years.
Darren Holmes, Nia Foster, Saima Ansari, Paul Kavanagh, Paul Dingwall, Peter C. Knipe   +5 more
wiley   +1 more source

Exploring Calixarene‐Based Pseudorotaxane Architectures: Threading Ammonium Axles With an Exo‐Rim π‐Functionalized Calix[6]Arene Macrocycle

Chemistry – A European Journal, EarlyView.
This research presents a novel 1,4‐π‐functionalized calix[6]arene with enhanced interactions with dialkylammonium axles. We investigate threading behavior in CDCl3, highlighting how exo‐rim π‐functionalization affects binding affinity and stereoselectivity.
Veronica Iuliano, Paolo Della Sala, Placido Neri, Donato De Simone, Rocco Del Regno, Margherita De Rosa, Carmine Gaeta, Carmen Talotta   +7 more
wiley   +1 more source

Enantiospecific Acid‐Catalysed Hydroperoxidation of Scalemic Tertiary Benzylic Alcohols Facilitating a Concise Asymmetric Synthesis of Yingzhaosu C

European Journal of Organic Chemistry, EarlyView.
Asymmetric synthesis of antimalarial yingzhaosu C was achieved in 4–5 steps by asymmetric Grignard synthesis of (R)‐gossonorol followed by novel enantiospecific hydroperoxidation. We report a concise asymmetric synthesis of antimalarial yingzhaosu C in 59% ee.
Saranna E. Kavanagh, Claudio Monasterolo, Declan G. Gilheany   +2 more
wiley   +1 more source

Stereoisomeric engineering mediated zinc metal electrodeposition: Critical balance of solvation and adsorption capability

Advanced Powder Materials
The exceptional electrochemical performance of zinc anodes is frequently impeded by inadequate deposition kinetics and interfacial chemistry. Herein, we introduce the stereoisomerism to inform the balanced selection of electrolyte additives, taking into ...
Wen Liu, Qiwen Zhao, Ruheng Jiang, Xuyan Ni, Tiancheng You, Canglong Li, Yanzi Deng, Bingang Xu, Yuejiao Chen, Libao Chen   +9 more
doaj   +1 more source

Catalytic Antioxidant Activity of Acyclic and Macrocyclic Selenides: Insights Into Structure–Activity Relationships and Mechanisms From Kinetic and Computational Studies

European Journal of Organic Chemistry, EarlyView.
Structure–activity relationships of antioxidant activities of selenides were established by experimental and computational methods. Several structures displayed strong catalytic activity in an NMR‐based assay. Diverse selenides were shown to act as potent catalytic antioxidants.
Adrian I. Doig, Wen Zhou, Thomas G. Back
wiley   +1 more source

Alkali cation-π interactions in aqueous systems, modulating supramolecular stereoisomerism of nanoscopic metal-organic capsules

Nature Communications
Contrary to common chemical intuition, cation-π interactions can persist in polar, aqueous reaction solutions, rather than in dry non-coordinative solvent systems.
Paul Wix, Swetanshu Tandon, Sebastien Vaesen, Kadri Karimu, Jennifer S. Mathieson, Kane Esien, Solveig Felton, Graeme W. Watson, Wolfgang Schmitt   +8 more
doaj   +1 more source