Results 101 to 110 of about 19,176 (260)

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

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

Beilstein Journal of Organic Chemistry
A valuable vinylogous addition reaction between 4-alkylidene-5-aminopyrazoles and alkyl trifluoropyruvates leading to highly functionalized tertiary alcohols bearing a trifluoromethyl group and a pyrazole ring is presented.
Judit Hostalet-Romero, Laura Carceller-Ferrer, Gonzalo Blay, Amparo Sanz-Marco, José R. Pedro, Carlos Vila   +5 more
doaj   +1 more source

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

Diastereoselectivity of Organometallic Additions to Nitrones

, 1988
Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only160 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.The diastereoselectivity of organometallic additions to nitrones bearing stereogenic ...
Chang, Zen-Yu
core  

Predicting the Diastereoselectivity of Rh-Mediated Intramolecular C−H Insertion

, 2016
Rhodium-mediated cyclization of the α-diazo ester 1 proceeds with high diastereoselectivity, to give the trisubstituted cyclopentane 5. A computational model (ZINDO and Molecular Mechanics) based on our current mechanistic understanding of the reaction ...
Arnold L. Rheingold (1274736), Kamfia K. You (2994519), Douglass F. Taber (1568878)   +2 more
core   +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

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

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

Rhodium‐Catalyzed Synthesis of Enantioenriched α‐Substituted Primary Amines Through Asymmetric Transfer Hydrogenation

Chemistry – A European Journal, EarlyView.
Enantioenriched α‐substituted primary amines are efficiently prepared by rhodium‐catalyzed asymmetric transfer hydrogenation of ortho‐hydroxyaryl N─H imines under mild conditions using a low catalyst loading and ammonium formate as the hydrogen source in high yields (up to 99%) and enantioselectivities (up to 99% ee).
Chonghuo Liu, Guillaume Lefèvre, Qin Yin, Phannarath Phansavath, Virginie Ratovelomanana‐Vidal   +4 more
wiley   +1 more source