Results 131 to 140 of about 39,817 (294)

β‐Quaternary α‐Amino Acids via Iridium‐Catalyzed Branched and Enantioselective Hydroalkylation of 1,1‐Disubstituted Styrenes

Angewandte Chemie, EarlyView.
A cationic Ir(I)‐complex modified with the chiral diphosphine DM‐SEGPHOS mediates the enantioselective hydroalkylation of diverse α‐substituted styrenes with N‐aryl glycine derivatives. The products are readily advanced to β‐quaternary α‐amino acids that are inaccessible or cumbersome to access by other means. Abstract A cationic Ir(I)‐complex modified
Fenglin Hong, Yihong Wang, L. Anders Hammarback, Craig M. Robertson, John F. Bower   +4 more
wiley   +2 more sources

Enantioselective PCCP Brønsted acid-catalyzed aza-Piancatelli rearrangement. [PDF]

, 2019
An enantioselective aza-Piancatelli rearrangement has been developed using a chiral Brønsted acid based on pentacarboxycyclopentadiene (PCCP). This reaction provides rapid access to valuable chiral 4-amino-2-cyclopentenone building blocks from readily ...
Delgado, Jose M, Hammersley, Gabrielle R, Nichol, Meghan F, Read de Alaniz, Javier, Steffens, Helena C, Veits, Gesine K   +5 more
core  

Organocatalytic Lewis base functionalisation of carboxylic acids, esters and anhydrides via C1-ammonium or azolium enolates [PDF]

, 2014
This tutorial review highlights the organocatalytic Lewis base functionalisation of carboxylic acids, esters and anhydrides via C1-ammonium/azolium enolates.
Morrill, Louis C., Smith, Andrew D.
core   +1 more source

Interrupted Barton–Zard Reaction/Friedel–Crafts Alkylation Telescoped Reaction for the Synthesis of Pyrrolo[3,4‐b]indole Cores

Asian Journal of Organic Chemistry, EarlyView.
An interrupted Barton–Zard reaction/Friedel–Crafts alkylation telescoped reaction provides aryl‐substituted pyrrolo[3,4‐b] cores in moderate‐to‐good yields as mostly single diastereomers. The reaction is tolerant of a wide range of electron‐deficient indoles and (hetero)aromatic nucleophiles, offering a modular approach for the synthesis of multi ...
Josip Rešetar, Karla Remar, Ana Mikleušević, Josipa Suć Sajko, Ines Bašić, Matija Gredičak   +5 more
wiley   +1 more source

Unlocking Lactonase Enzymes as Biocatalysts for the Deracemisation of Chiral γ‐Thiolactones

Angewandte Chemie, EarlyView.
The application of lactonase enzymes as biocatalysts still remains underexplored. This study discloses the biocatalytic activity of two lactonases in the deracemisation of chiral C3‐substituted‐γ‐thiolactones. The biocatalyst GcL catalyses the enzymatic kinetic resolution (EKR) of C3‐amide‐thiolactones, while the rationally engineered biocatalyst N9 ...
Jingyue Wu, Michele Crotti, Ivan Bassanini, Mahdi Hassankalhori, Erica Elisa Ferrandi, Ferran Sancho, Daniela Monti, Daniele Castagnolo   +7 more
wiley   +2 more sources

Enantioselective manipulation of chiral nanoparticles using optical tweezers [PDF]

arXiv, 2019
We put forward an enantioselective method for chiral nanoparticles using optical tweezers. We demonstrate that the optical trapping force in a typical, realistic optical tweezing setup with circularly-polarized trapping beams is sensitive to the chirality of core-shell nanoparticles, allowing for efficient enantioselection.
arxiv  

Enantiopure Chiral Crystals: A Powerful Tool for Absolute Asymmetric Synthesis

Asian Journal of Organic Chemistry, EarlyView.
This review covers absolute asymmetric syntheses, which allow the preparation of enantiomerically enriched chiral compounds from achiral precursors. By exploiting the crystallization of certain compounds as a conglomerate, enantiopure chiral crystals are spontaneously obtained.
Jiacheng Li, Valérie Alezra
wiley   +1 more source

Cooperative Photometallobiocatalysis: Nonheme Fe Enzyme‐Catalyzed Enantioconvergent Radical Decarboxylative Azidation, Thiocyanation, and Isocyanation of Redox‐Active Esters

Angewandte Chemie, EarlyView.
Through the directed evolution of an underexploited nonheme Fe extradiol dioxygenase, we developed a unified cooperative photobiocatalytic strategy to allow for three types of enantioconvergent radical transformations, including azidation, thiocyanation, and isocyanation.
Liu‐Peng Zhao, Ken Lin, Pei‐Pei Xie, Huichong Liu, Hengye Xiang, Xin Liu, Yunlong Zhao, Peng Liu, Yang Yang   +8 more
wiley   +2 more sources

Exploiting 3‐Methyleneisoindolinones as In Situ Generated Reactive Intermediates in the Synthesis of Tetrasubstituted Carbon Center

Asian Journal of Organic Chemistry, EarlyView.
A straightforward method for constructing a tetrasubstituted carbon center through the in situ formation of 3‐methyleneisoindolinones as reactive intermediates has been developed. This process involves an acid‐catalyzed Meyer‐Schuster rearrangement of isoindolinone‐based propargylic alcohols, followed by an intermolecular Friedel‐Crafts alkylation ...
Arben Beriša, Filip Duplić, Marko Purić, Matija Gredičak, Nikola Topolovčan   +4 more
wiley   +1 more source

Enantioselective cycloaddition reactions

ChemInform, 1991
Publisher Summary This chapter reviews the cycloadditions reactions because they are popular, widely used, and also constitutes enormous body of chemistry. The chapter focuses on the landmark achievements as well as state-of-the-art examples of relevant chemistry.
openaire   +3 more sources