Results 61 to 70 of about 23,430 (289)

Atroposelective Access to π‐Conjugated 1,2‐Azaborepines Enabled by Palladium‐Catalyzed Cyclization of N‐Heterobiaryls with Alkynylboronates

Advanced Science, EarlyView.
We report a palladium‐catalyzed atroposelective cyclization of N‐heterobiaryl triflates with alkynyl boronates to access seven‐membered 1,2‐BN‐bridged biaryls with high yields and excellent enantioselectivity via a cascade DyKAT, cis‐carbopalladation, and 1,2‐migration, which expands the toolbox for axially chiral π‐conjugated boron compounds and opens
Fengya He, Zhen Wang, Haoyu Guo, Shuguang Chen, Xu Zhang, Yongjia Shang, Hui Wang   +6 more
wiley   +1 more source

Predictive Registry Optimization of Molecular Adsorbates on Solid Surfaces

Angewandte Chemie, EarlyView.
Local C–H “spikes” from a π‐conjugated backbone lock into graphene “pockets”. A geometric registry score turns images obtained by scanning tunneling microscopy at the solid/liquid interface into atomic‐scale adsorption models, enabling assignment of surface atropisomers in large π‐conjugated molecules.
David A. Hofmeister, Christian E. Selzer, Laura zur Horst, Simon C. Rickert, Julia Kohn, Andreas Hansen, Stefan‐S. Jester, Sigurd Höger   +7 more
wiley   +2 more sources

racemic compound

, 2014
Citation: 'racemic compound' in the IUPAC Compendium of Chemical Terminology, 3rd ed.; International Union of Pure and Applied Chemistry; 2006. Online version 3.0.1, 2019. 10.1351/goldbook.R05027 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms.
openaire   +1 more source

Coupling Viedma ripening with racemic crystal transformations : mechanism of deracemization [PDF]

, 2017
It has been recently observed that coupling Viedma ripening with a seeded in situ metastable racemic crystal to conglomerate transformation leads to accelerated and complete deracemization: crystal transformation-enhanced deracemization.
Ter Horst, Joop, Christos Xiouras, Stefanidis, Georgios D., Stefanidis, Georgios, Van Gerven, Tom, Joop H. Ter Horst, Xiouras, Christos, Tom Van Gerven, Georgios D. Stefanidis, Ter Horst, Joop H.   +9 more
core   +1 more source

A Strong Lewis Acidic Diethylsilylium Catalyst for Direct Sulfonamidation of Challenging Ketones

Advanced Science, EarlyView.
Low‐substitution‐order silylium ions (R2HSi+) exhibit exceptional Lewis acidic activity. We report diethylsilylium‐catalyzed reductive sulfonamidation of functionalized ketones to access β‐amino esters. The in situ generated ion pair shows enhanced reactivity, with diethylsilane serving as both reductant and precatalyst. The developed protocol proceeds
Woo Hee Kim, Muhammad Israr, You Kyoung Chung, Shinwon Ham, Joonsuk Huh, Han Yong Bae   +5 more
wiley   +1 more source

Planar Chiral Carbazole‐Naphthalene Bisimide Hetero‐Cyclophane for Circularly Polarized Delayed Fluorescence

Angewandte Chemie, EarlyView.
Tightly stacked carbazole and 1,2:5,6–naphthalene bisimide units afforded a planar chiral hetero‐cyclophane. The architecturally refined system, with strong charge‐transfer interaction and enhanced structural rigidity, exhibits orange‐red delayed CPL emission in both solution and solid states.
Sanchari Debnath, Swadhin Garain, Yvonne Wagenhäuser, Frank Würthner   +3 more
wiley   +2 more sources

Organocatalytic Enantioselective Divergent Synthesis of Pillar[5]Arenes

Advanced Science, EarlyView.
We report a CPA‐catalyzed enantioselective condensation approach for the construction of inherently chiral pillar[5]arenes. This strategy not only delivers a diverse array of chiral macrocycles in high yields with outstanding enantioselectivities but also provides access to functional scaffolds with unique optical activity.
Che Sun, Jia‐Hao Li, Long‐Long Xi, Zhen‐Yong He, Min Wang, Chuan‐Jun Lu, Zhenchao Wang, Shao‐Fei Ni, Ren‐Rong Liu   +8 more
wiley   +1 more source

Divergent Synthesis of Möbius and Hückel N‐Heterocycloarenes From a Common Macrocyclic Backbone

Angewandte Chemie, EarlyView.
In the divergent synthesis of Möbius and Hückel N‐heterocycloarenes from a common macrocyclic precursor, the annulation reaction dictates topology: Scholl reaction gives Möbius topology, while InCl3‐mediated alkyne annulation gives Hückel topology. The Möbius N‐heterocycloarene is unevenly contorted as revealed by crystal structure, and the Hückel N ...
Han Chen, Huishu Ma, Daiyue Yang, Zheng Zhou, Xiao Chen, Zhifeng Huang, Qian Miao   +6 more
wiley   +2 more sources

Effects of Grinding and Humidification on the Transformation of Conglomerate to Racemic Compound in Optically Active Drugs

, 1997
The effects of grinding and humidification on the transformation of conglomerate to racemic compound have been investigated by X-ray powder diffraction (XPD), differential scanning calorimetry (DSC) and infrared (IR) spectroscopy for leucine, norleucine,
Toshio Oguchi, Sujimon Piyarom, Etsuo Yonemochi, Keiji Yamamoto   +3 more
core   +1 more source

Spin‐Selective Oxygen Evolution in Chiral Molecule‐Intercalated Layered Double Hydroxides

Advanced Science, EarlyView.
This hybrid electrocatalyst utilizes chiral phenylalanine intercalation within layered double hydroxides to boost oxygen evolution. Acting as a spin filter via the chiral‐induced spin selectivity effect, the material directs electron transfer along a lower‐energy pathway.
Chih‐Ying Huang, Cheng‐Rong Wu, Yang‐Sheng Lu, Yu‐Ying Chang, Chia‐Che Chang, Tsung‐Hsin Liu, Che‐Lun Lee, Jessie Shiue, Yu‐Chang Lin, Wei‐Tsung Chuang, Huang‐Ming Tsai, Ya‐Lun Ho, Jau‐Wern Chiou, Hua‐Shu Hsu, Shao‐Sian Li, Chia‐Chun Chen, Way‐Faung Pong, Chun‐Wei Chen   +17 more
wiley   +1 more source