Results 81 to 90 of about 81,226 (245)

Chiroptical Switching by Stereoselective Photochemical Sigmatropic Rearrangements: Experimental Realization of Calderoselectivity

Angewandte Chemie, EarlyView.
Calderoselectivity is established as a stereochemical principle for sigmatropic rearrangements. A homoannulene‐based chiroptical photoswitch undergoes a photochemical [1,11] sigmatropic rearrangement with control of the acyl movement on top of the cyclic π system.
Anne Krenkel, Frederike Beyer, Malte Feßner, Trung Tran Ngoc, Tobias Rüffer, Dominik Hornig, Martin Breugst, Christian Merten, Johannes F. Teichert   +8 more
wiley   +2 more sources

Novos materiais poliméricos furânicos baseados na reacção reversível de Diels-Alder [PDF]

, 2011
Doutoramento em QuímicaA futura e inevitável escassez dos recursos fósseis, juntamente com o aumento imprevisível dos seus preços, levou, nas últimas décadas, a um aumento impressionante de iniciativas dedicadas não só à procura de fontes alternativas
Coelho, Dora Salomé Correia
core  

Tandem inverse electron demand Diels-Alder, retro Diels-Alder and intramolecular Diels-Alder sequences : one-pot synthesis of diaza-polycycles

, 2007
A new and straightforward methodology is described for the construction of complex nitrogen-containing polycycles from substituted 1,2,4-triazines and enamines, prepared in situ from carbonyl components and allylic amines. The transformation proceeds via
Bromley, William, Lang, Stuart, Raw, Steven, Gibson, Mairi, Whitwood, Adrian, Taylor, Richard   +5 more
core   +3 more sources

REACTION OF 4-METHYL- 1 2,4-TRIAZOLINE- 3,5-DIONE WITH DI AND TRI-SUBSTITUTED STYRENES S.E. Mallakpour* and G.B. Butler** [PDF]

Journal of Sciences, Islamic Republic of Iran, 1993
2,4,6-Triisopropylstryrene was synthesized in a single step via the Witting Reaction from the corresponding aldehyde. The reaction of three styrene's derivatives, 2,6-dimethylstyrene, 2,4,6-trimethylstyrene, and 2,4,6- triisopropylstyrene with 4-methyl-l,
doaj  

High-level Computational Study of the Site-, Facial- and Stereoselectivities for the Diels-Alder Reaction Between o-Benzoquinone and Norbornadiene

Molecules, 2000
Ab initio and DFT quantum chemical calculations have been applied to a study of the Diels-Alder reaction of o-benzoquinone as diene and norbornadiene as dienophile.
Ronald N. Warrener, Martin R. Johnston, Davor Margetic   +2 more
doaj   +1 more source

Aktivierung von Metallkomplexen durch Ultraschallwellen für eine gezielte Krebstherapie

Angewandte Chemie, EarlyView.
Ultrasound enables non‐invasive activation of metal‐based therapeutics deep within tumors. Acoustic cavitation can drive sonodynamic reactive oxygen species generation or mechanochemical metal–ligand bond dissociation, enabling controlled release of bioactive payloads.
Félix Grosjean, Nicolás Montesdeoca, Gilles Berger, Johannes Karges   +3 more
wiley   +1 more source

Substituent Effects on Regioselectivity of the Diels-Alder Reactions: Reactions of 10-Allyl-1,8-dichloroanthracene with 2-Chloroacrylonitrile, 1-Cyanovinyl Acetate and Phenyl Vinyl Sulfone

Journal of Chemistry, 2016
Diels-Alder reaction of 10-allyl-1,8-dichloroanthracene (3) with 2-chloroacrylonitrile (4) and 1-cyanovinyl acetate (5) gives exclusively the ortho isomer while its reaction with phenyl vinyl sulfone (10) yields a mixture of two isomeric adducts with ...
Mujeeb A. Sultan, Usama Karama
doaj   +1 more source

Estudos sobre o uso do NbCl5 como ácido de Lewis em reações de Povarov

Orbital: The Electronic Journal of Chemistry, 2011
RESUMO: O objetivo deste trabalho foi investigar o uso de NbCl5 como ácido de Lewis em reações de cicloadição (Reação Aza-Diels-Alder (Povarov)) entre bases de Schiff e éteres enólicos.
Luiz Carlos Silva-Filho, Mayara Frenhe
doaj   +1 more source

Synthese einer Stabilen, Hydrophilen Trans‐Cycloocten‐Aminosäure Ermöglicht Schnelle Bioorthogonale Klick‐Chemie zur Herstellung von Antikörper‐Wirkstoffkonjugaten Mittels Erweiterung des Genetischen Codes

Angewandte Chemie, EarlyView.
Es wird von einer neuen trans‐Cycloocten (TCO) basierten nicht‐kanonischen Aminosäure (ncAA) berichtet, die von einer hohen Hydrophilizität und bemerkenswerter Stabilität gegen trans‐cis‐Isomerisierung charakterisiert ist. Der Einbau dieser mittels Erweiterung des genetischen Codes in einen Antikörper und nachfolgende Konjugation erzeugte ein ...
Georgi R. Genov, Dina Osmanović, Ines Bašić, Christine Koehler, Paul F. Sauter   +4 more
wiley   +1 more source

Synthesis of Unsymmetrical Annulated 2,2’-Bipyridine Analogues with Attached Cycloalkene and Piperidine Rings via Sequential Diels-Alder Reaction of 5,5’-bi-1,2,4-triazinesâ€

Molecules, 2005
Synthesis of bisfunctionalized unsymmetrical 2,2’-bipyridines 8 or their sulfonyl derivatives 12a,b are described. They were prepared via the Diels-Alder reaction of 1-methyl-4-pyrrolidin-1-yl-1,2,3,6-tetrahydropyridine (6) with 3,3’-bis(methyl-
D. Branowska
doaj   +1 more source