Results 71 to 80 of about 8,448 (224)

Facile Chemical Access to Biologically Active Norcantharidin Derivatives from Biomass

Molecules, 2017
Reductive amination of 2,5-diformylfuran (DFF) was used to implement the transition from bio-derived 5-hydroxymethylfurfural (HMF) to pharmaceuticals.
Konstantin I. Galkin, Fedor A. Kucherov, Oleg N. Markov, Ksenia S. Egorova, Alexandra V. Posvyatenko, Valentine P. Ananikov   +5 more
doaj   +1 more source

Catalytic Generation of Cationic Gold Carbene Complexes From 7‐Alkynylnorbornadienes and Their Intermolecular Cyclopropanation With Alkenes

Chemistry – A European Journal, EarlyView.
Efficient cationic gold(I)‐catalyzed intermolecular cyclopropanation of 7‐alkynylnorbornadiene derivatives has been developed. This methodology offers the synthesis of a new class of norbornene derivatives in high yield with excellent diastereoselectivity.
Kento Ishida, Kenta Toei, Fumiaki Tomi, Norio Sakai   +3 more
wiley   +1 more source

N‐Aryl Acridone Derivatives as Effective Catalysts for Energy Transfer Reactions

Chemistry – A European Journal, EarlyView.
Acridones derivatives have high triplet energy, are simple accessible, and could be used in challenging [2+2] ENT reactions. ABSTRACT Organic photocatalysts capable of promoting high‐energy triplet energy transfer (EnT) remain limited, particularly for demanding [2+2] photocycloaddition reactions.
Francesco Calogero, Gaetano D'Onghia, Federica Fina, Zakaria Ziani, Luca Sensoli, Andrea Gualandi, Andrea Fermi, Paola Ceroni, Pier Giorgio Cozzi   +8 more
wiley   +1 more source

Covalent Insertion of a Mn(Salen) Type Complex in Cross‐Linked Protein Crystals: Design of an Enantioselective Artificial Epoxidase

Chemistry – A European Journal, EarlyView.
An Artificial metalloenzyme was designed by a Michael addition between a MnSalen complex and a cysteine residue within NikA crystals. The heterogeneous catalyst was found capable of an enantioselective and stereospecific epoxidation of cis‐β‐methylstyrene in cristallo.
Manel Boukhallat, Ismail Benhamed, Jade Arnone, Stann Van Baaren, Clara Rinaldi, Patrice Catty, Caroline Marchi‐Delapierre, Christine Cavazza, Stéphane Ménage   +8 more
wiley   +1 more source

Titanium‐Catalyzed Diastereoselective Keto‐ and Iminonitrile Cyclizations

Chemistry – A European Journal, EarlyView.
The titanium(III)‐catalyzed diastereoselective cyclization of readily‐available substituted ketonitriles gives cyclopentanones in good yield and stereoselectivity. Subsequent 1,2‐addition allows the preparation of cyclopentyls with three consecutive stereocenters.
Christoph Kern, Ritu Singh, Michael A. Unkrig‐Bau, Lukas Jakob, Jan Streuff   +4 more
wiley   +1 more source

Oxidising agent and catalyst chirality effect on epoxidation of R-(+)-Limonene using Jacobsen-type catalysts

Ingeniería e Investigación, 2008
The oxidising agent effect on R-(+)-Limonene epoxide diastereoselectivity using chiral and achiral Jacobsen’s type catalysts is presented. The type of oxidising agent strongly influences diastereoselectivity.
Juliana Reyes Calle, Jairo Antonio Cubillos Lobo, Consuelo Montes de Correa, Aída Luz Villa Holguín de P.   +3 more
doaj  

FLP Mediated Conversion of Difluorobenzylalkynes to Fluoroallenyl Oniums via an SN1’ Pathway

Chemistry – A European Journal, EarlyView.
Frustrated Lewis pair (FLP) selective C‒F activation of difluorobenzylalkynes allows the formation of fluoroallenic oniums via an SN1’ substitution pathway. The fluoroallenic onium salts are synthetic precursors that allow subsequent functionalization at allenic and onium positions.
Max Coles, Tianhong Wang, Rubi McLennan, Long Kit Kwan, Bivas Mondal, Chakyu Richard Chan, Rowan D. Young   +6 more
wiley   +1 more source

Ringing the Changes: Effects of Heterocyclic Ring Size on Stereoselectivity in [(η⁵-C₅Me₅)RhCl], [(η⁵-C₅Me₅)IrCl] and [Ru(η⁶-cymene)Cl] Complexes of Chiral 3-Amino-1-Azacycles

Molecules
Ring size-dependent diastereoselective coordination of unsymmetrical diamines containing one azacyclic nitrogen and one exocyclic nitrogen to [(η5-C5Me5)MCl]+ cores where M = Rh, Ir and [Ru(η6-cymene)Cl]+ is reported herein.
Vladimir Y. Vladimirov, Matheo Charrier-Chardin, Benson M. Kariuki, Benjamin D. Ward, Paul D. Newman   +4 more
doaj   +1 more source

Nitrooxylation in Organic Synthesis: From Classical Nitrate Ester Formation to Modern Catalytic Strategies

Chemistry – A European Journal, EarlyView.
Nitrooxylation—the installation of nitrate esters (–ONO2) has evolved from classical mixed‐acid protocols to catalytic and mechano‐, flow‐, photo‐, and electrochemical strategies. This review delineates ionic and radical manifolds for C–ONO2 bond formation, emphasizing mechanistic control, selected substrate scope, and selectivity.
Jayanta Dey, Dmitry Katayev
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