Results 81 to 90 of about 8,448 (224)

Diastereoselective synthesis of 3,4-dihydro-2H-pyran-4-carboxamides through an unusual regiospecific quasi-hydrolysis of a cyano group

Beilstein Journal of Organic Chemistry, 2016
An efficient diastereoselective approach for the synthesis of functionalized 3,4-dihydro-2H-pyran-4-carboxamides with variable frame was developed based on the reaction of available 4-oxoalkane-1,1,2,2-tetracarbonitriles (adducts of TCNE and ketones ...
Mikhail Yu. Ievlev, Oleg V. Ershov, Mikhail Yu. Belikov, Angelina G. Milovidova, Viktor A. Tafeenko, Oleg E. Nasakin   +5 more
doaj   +1 more source

Relay Approach: A Convergent Synthesis of Key Fragments en route to (+)‐Neosorangicin A

Chemistry – A European Journal, EarlyView.
A selective synthesis of three key fragments of the antibiotically active (+)‐neosorangicin A is reported, providing a foundation for its convergent total synthesis and proof of strategy via a relay approach. ABSTRACT Herein, we report the synthesis of the three key fragments of the macrolide antibiotic (+)‐neosorangicin A, a compound exhibiting potent
Marvin Wenninger, Maxim Munt, Le Chang, Rositsa Stoykova, Roberto Ojcius, Oliver Spieß, Dieter Schinzer   +6 more
wiley   +1 more source

Stereochemical Control in the Matteson Reaction

Chemistry – A European Journal, EarlyView.
The Matteson homologation is a highly versatile method for the stereoselective insertion of carbenoids into boronic esters. Through iterative application of the process, complex chiral molecules can be synthesized. The stereoselectivity of the reaction is determined by a chiral diol incorporated in the boronic ester.
Hae Mo Lee, Christoph Hirschhäuser
wiley   +1 more source

Cyclopropylamine‐Derived Distonic Iminium Radicals: Photoinduced Strategies in Chemo‐ and Stereo‐Selective Synthesis

Chemistry – A European Journal, EarlyView.
Cyclopropylamines have emerged as powerful photocatalytic building blocks. Upon light‐induced single‐electron oxidation, they undergo strain‐release ring opening to generate distonic iminium radicals that enable diverse transformations, including ring‐opening functionalization, formal [3 + 2] cycloadditions, radical cascades, and asymmetric bond ...
Maria Chiara Cabua, Alberto Luridiana, Francesco Secci, Emanuele Cocco   +3 more
wiley   +1 more source

Avanços recentes na química dos aminoaçúcares: ocorrência, biossíntese, síntese e aplicação

Química Nova
Amino sugars are chemical compounds that have a sugar backbone, in which one of the hydroxyl groups is replaced by an amino group. Derivatives of amine-containing sugars, such as N-acetylglucosamine, are also considered amino sugars.
Aldicéia Luiz de Moura, Bruna Martins Guimarães, Josefa Aqueline da Cunha Lima, Mauricélia M. Sousa Mata, Jadson Farias da Silva, Ronaldo N. Oliveira, Juliano Carlo Rufino de Freitas, João R. de Freitas Filho   +7 more
doaj   +1 more source

Regioselective Aldol Reactions Directed by Charge and Orbital Effects in Cyclic Germyl Dienolates: Synthesis of Three Distinct Regio‐ and Stereoisomers

Chemistry – A European Journal, EarlyView.
Charge and orbital control represent fundamental principles in organic chemistry. In this study, these principles are applied to the aldol reactions of a cyclic Ge‐dienolate. By systematically tuning the charge and orbital distributions of the Ge‐dienolates and their aldehyde reaction partners, regio‐ and stereoselective access to three distinct aldol ...
Taishi Nojima, Akihito Konishi, Makoto Yasuda   +2 more
wiley   +1 more source

Multicomponent Hosomi–Sakurai Reaction on Isosorbide Derivatives

Molecules
Trimethylsilyl ethers of monoprotected isosorbide derivatives have been subjected to multicomponent Hosomi–Sakurai reactions with allyl trimethylsilane and various aldehydes (aromatic or aliphatic) under the catalysis of trimethylsilyl triflate.
Luca Banfi, Lucia Garcia de la Parte, Chiara Lambruschini, Lisa Moni, Daniel Rufo Perez, Renata Riva   +5 more
doaj   +1 more source

Diastereoselectivity in Photochemistry

International audience ; Diastereoselective photochemical reactions play an important role for asymmetric synthesis, for example for the synthesis of natural or biologically active compounds. Chirality is either induced by a chiral auxiliary or by a chiral centers already present in the substrates.
openaire   +2 more sources

Chiral Pyrazolinylidene Complexes for Asymmetric Catalysis

Chemistry – A European Journal, EarlyView.
The synthesis and application of pyrazolin‐5‐ylidene NHC chiral‐at‐ruthenium catalysts is reported. The strong donating pyrazolin‐5‐ylidene ligands led to highly electron rich ruthenium complexes, which showed excellent catalytic activity and enantioselectivity in the intramolecular aziridination of an alkene.
Felix Möller, Nemrud Demirel, Thomas Krüger, Linus Plohnke, Jennifer Schröder, Sergei I. Ivlev, Eric Meggers   +6 more
wiley   +1 more source

The Mechanism of Visible‐Light Photochemical Rearrangements of Conjugated Amide Enolates

Chemistry – A European Journal, EarlyView.
Visible light irradiation of extended enolates of N‐benzylamides leads to homolytic C─N Bond cleavage, generating a biradical. Computational and mechanistic studies suggest rapid radical recombination within a solvent cage to give either ring‐expanded or rearranged products. ABSTRACT Deprotonation of conjugated amides forms colored solutions of lithium
James Mortimer, William Terry‐Wright, Basile F. E. Curchod, Jonathan Clayden   +3 more
wiley   +1 more source