Results 81 to 90 of about 6,473 (220)

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

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

Enantio-, atrop-, and diastereoselective macrolactonization to access type III cyclophanes

Nature Communications
Although chiral substituents have been incorporated into ansa chains to stabilize the conformations of cyclophanes and modulate the biological activities of pharmaceuticals, the asymmetric syntheses of these atropisomers relies on substrate-induced ...
Jiaming Wang, Kang Lv, Yilu Wen, Tao Liu, Changgui Zhao   +4 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

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

Isotelluroureas for Asymmetric C1 Ammonium Enolate Reactions

European Journal of Organic Chemistry, EarlyView.
Chiral isotelluroureas are powerful catalysts for a variety of C─C bond forming C1 ammonium enolate transformations. Isotelluroureas (ITeUs) have recently been introduced as a novel class of highly nucleophilic Lewis base catalysts. Herein, we systematically screened them for their potential to facilitate C1 ammonium enolate transformations and ...
Fereshteh Khorasani, Lotte Stockhammer, Magdalena Piringer, Mario Waser   +3 more
wiley   +1 more source

Stereoselective Construction of Benzo‐Fused Tetrahydropyrrole Thiazines From Saccharin

European Journal of Organic Chemistry, EarlyView.
Saccharin was used as a template to construct a series of 10a‐substituted, benzo‐fused, pyrrolo thiazinone dioxides. Thereafter, diastereo‐divergent 10‐keto reduction gave either diastereomeric alcohol in a process that did not rely on the substituent at 10a's identity.
Seanán Doyle, Matthew Kiernan, Jordan Smyth, Ajay Mathew, Conor J. Crawford, Julia Bruno‐Colmenarez, Patrick J. Guiry, Aisha Khalifa, Paul Evans   +8 more
wiley   +1 more source

Diastereoselective Synthesis of Highly Substituted Methylene Cyclobutanes by Pd Catalysis

European Journal of Organic Chemistry, EarlyView.
A chemo‐ and diastereoselective palladium‐catalyzed intramolecular coupling/cyclization of borylated 1,5‐dienes, readily accessible by allene allylboration, with iodoarenes enables the synthesis of highly substituted methylene cyclobutanes. The method exhibits broad scope, high functional group tolerance, and complete enantiospecificity.
Jose M. Malga, Martín Fañanás‐Mastral   +1 more
wiley   +1 more source