Results 101 to 110 of about 83,738 (273)

Cation-induced enhanced enantioselective recognition by a chiral covalent-organic framework

Communications Chemistry
Chirality plays a pivotal role in the properties of biologically active molecules, with enantiomers exhibiting divergent pharmacological and toxicological profiles.
Zongsu Han, Tiankai Sun, Peng Cheng, Wei Shi   +3 more
doaj   +1 more source

Enantioselective synthesis of aziridines using asymmetric transfer hydrogenation as a precursor for chiral derivatives used as bonding agent for rocket solid propellants

Química Nova, 2002
A rapid, expedient and enantioselective method for the synthesis of beta-hydroxy amines and monosubstituted aziridines in up to 99% e.e., via asymmetric transfer hydrogenation of a-amino ketones and cyclisation through treatment with tosyl chloride and ...
Aparecida M. Kawamoto, Martin Wills
doaj   +1 more source

Asymmetric [3 + 2] Cycloaddition to Access 3‐Pyrrolines and Their Switchable Transformations to Nine‐Membered Cyclic Sulfamidates and 2H‐Pyrroles

Advanced Science, EarlyView.
Pd‐catalyzed asymmetric [3 + 2] cycloaddition of cyano‐TMM with cyclic sulfamidate imines affords chiral 3‐pyrrolines bearing endocyclic olefins. Simple solvent and temperature adjustments under identical basic conditions enable chemo‐switchable one‐pot ring expansion or desulfonylation, providing a unified access to medium‐sized sulfamidates and 2H ...
Seoung‐Mi Choi, Jong‐Un Park, Ju Hyun Kim   +2 more
wiley   +1 more source

Spatial Assembly of Mechanically Planar Chiral Rotaxanes on Rationally Designed Cavitands

Angewandte Chemie, EarlyView.
A spatial molecular assembly strategy enables the synthesis of enantioenriched mechanically planar chiral rotaxanes. Inherently chiral cavitands are rationally designed to encode and transmit the stereochemical information. Predictable stereochemical induction is achieved by controlling the spatial arrangement of molecular components through ...
Liwen Xia, Wenyang Hong, Chong Tian, Ye Zhu   +3 more
wiley   +2 more sources

A Modular Chemoenzymatic Cascade Simplifies Divergent Synthesis of Natural and Unnatural Benzylisoquinoline Alkaloids

Advanced Science, EarlyView.
A simplified chemoenzymatic platform is designed to integrate an enzyme cascade with subsequent chemical steps, enabling the divergent production of diverse benzylisoquinoline alkaloids (BIAs). Demonstrating remarkable versatility and enantioselectivity, four distinct classes of BIAs are efficiently generated, in which the natural medicine papaverine ...
Huiling Liu, Zhenbo Yuan, Yue Gao, Fei Li, Zhiwei Deng, Yan Zhang, Zhengshan Luo, Changmei Liu, Yijian Rao   +8 more
wiley   +1 more source

Cooperative Brønsted Acid and Photo‐Promoted Stereoselective Synthesis of Substituted Piperidones

Angewandte Chemie, EarlyView.
A Brønsted acid cooperates with a photoexcited carbonyl triplet to promote stereoselective C─C bond formation in disubstituted piperidones through a chromophore‐activator strategy. The Brønsted acid lowers the excitation energy gap, directs selective C─N bond cleavage over C─C fragmentation after H‐atom transfer, and enables enantioselective C─C bond ...
Qiupeng Peng, Poulami Mukherjee, Adhya Suresh, Meemie Hwang, Osvaldo Gutierrez, Karl A. Scheidt   +5 more
wiley   +2 more sources

Crossing the Oxo‐Peroxo Wall for Selective Electrochemical Epoxidation

Advanced Science, EarlyView.
The classical Oxo‐Wall concept is extended to an Oxo–Peroxo Wall framework, showing that meta‐stable oxo species favor peroxo and superoxo formation, decoupling from oxygen evolution reaction (OER). This new understanding enables selective C‐C bond oxidations and provides a predictive alternative oxidation reaction (AOR) volcano for designing metal ...
Pooja Basera, Shyama Charan Mandal, Frank Abild‐Pedersen, Michal Bajdich   +3 more
wiley   +1 more source

Enantioselective Syntheses of Secondary Alkylboronates via Asymmetric Regioselective Reduction of 1,3‐Dienylboronates

Angewandte Chemie, EarlyView.
We report herein the development of catalytic asymmetric synthesis of secondary alkyl boronates. Under the optimal conditions, Cu‐catalyzed semi‐reduction of 1‐alkyl‐ or 1,3‐dialkyl‐substituted 1‐boryl‐1,3‐butadienes forms secondary alkyl boronates with excellent regioselectivities and enantioselectivities.
Wen‐Bin Cao, Lingfei Hu, Jiaming Liu, George Chen, Gang Lu, Ming Chen   +5 more
wiley   +2 more sources

Synthesis of the tetracyclic core of Illicium sesquiterpenes using an organocatalyzed asymmetric Robinson annulation

Beilstein Journal of Organic Chemistry, 2013
An enantioselective synthesis of the core framework of neurotrophic Illicium majucin-type sesquiterpenes is described here. This strategy is based on an organocatalyzed asymmetric Robinson annulation and provides an efficient approach for a diversity ...
Lynnie Trzoss, Jing Xu, Michelle H. Lacoske, Emmanuel A. Theodorakis   +3 more
doaj   +1 more source

Organocatalytic stereodivergent synthesis of β,β-disubstituted-α-aminoacids [PDF]

, 2017
In this work, we present an organocatalytic stereodivergent synthesis of β,β-disubstituted-α-aminoacids using arylidene azlactones as starting materials.
Martinelli, Ada
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