نتایج جستجو برای: conjugated diene value

تعداد نتایج: 762715  

2017
Radomir Jasiński Karolina Kula Agnieszka Kącka Barbara Mirosław

ABSTRACT Reactions between (E)-2-aryl-1-cyano-1-nitroethenes and diazafluorene lead to acyclic 2,3-diazabuta-1,3-diene derivatives, instead of the expected pyrazoline systems. DFT calculations suggest that this is a consequence of formation of zwitterionic structure in the first stage of the reaction. It must be noted that this is a specific property of the (E)-2-aryl-1-cyano-1-nitroethenes gro...

Journal: :Journal of the American Chemical Society 2014
Sarah E Parker Jonas Börgel Tobias Ritter

Selective 1,2-hydrosilylation of 1,3-dienes is a challenging problem in transition metal catalysis. Butadiene, specifically, would be a useful substrate because 3-butenylsilane products have promise as superior coupling reagents for hybrid organic/inorganic materials synthesis. We report the first selective 1,2-hydrosilylation of conjugated dienes including butadiene. Hydrosilylation proceeds t...

1999
Hans-Joachim Knölker

The protection of conjugated dienes by coordination to the tricarbonyliron fragment offers many potential applications of the resulting complexes to organic synthesis. The preparation of tricarbonyl(h4-1,3-diene)iron complexes is readily achieved by a 1-azabutadiene-catalyzed complexation of the free ligands. An asymmetric catalytic complexation of prochiral cyclohexa-1,3-dienes with pentacarbo...

2008
Judith C. Gallucci Robert D. Dura Leo A. Paquette

The title compound, C(12)H(12)BrNO(2)S, was isolated after direct irradiation (hν 350 nm, hexa-ne) of a mixture of stereoisomeric sulfonamides containing a vicinal dibromide and a conjugated diene. This product is one of a group of substrates that has contributed to our understanding of the photoreactivity patterns of non-bridged sulfonamides. The crystal structure was determined from a non-mer...

Background: Due to the adverse effects of artificial preservatives on food and its harmful effects on human health, researchers have been considering replacing these materials with natural substances. In this study, the effect of pomegranate peel extract (PPE) on the stability and antifungal activity of the walnut kernel was studied. Methods: The pomegranate peel was extracted by the solvent ...

Journal: :Bioscience, biotechnology, and biochemistry 2003
Takanobu Nishida Van Le Vang Hiroyuki Yamazawa Ryuji Yoshida Hideshi Naka Koji Tsuchida Tetsu Ando

Hexadecadien-1-ol and the derivatives (acetate and aldehyde) with a conjugated diene system have recently been identified from a pheromone gland extract of the persimmon fruit moth (Stathmopoda masinissa), a pest insect of persimmon fruits distributed in East Asia. The alcohol and acetate showed their base peaks at m/z 79 in a GC-MS analysis by electron impact ionization, but the aldehyde produ...

2015
Xijian Li Siyu Peng Li Li Yong Huang

Electron-rich dienes have revolutionized the synthesis of complex compounds since the discovery of the legendary Diels-Alder cycloaddition reaction. This highly efficient bond-forming process has served as a fundamental strategy to assemble many structurally formidable molecules. Amino silyloxy butadienes are arguably the most reactive diene species that are isolable and bottleable. Since the p...

Journal: :Angewandte Chemie 2011
Ranjan Jana James J Partridge Jon A Tunge

A three-component coupling of vinyl triflates and boronic acids to alkenes catalyzed by palladium is reported. Using 1,3-dienes, selective 1,2-alkene difunctionalization is observed, whereas the use of terminal alkenes results in 1,1-alkene difunctionalization. The reaction outcome is attributed to the formation of stabilized, cationic Pdπ-allyl intermediates to regulate β-hydride elimination. ...

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