scholarly journals Highly stereocontrolled synthesis of trans-enediynes via carbocupration of fluoroalkylated diynes

2012 ◽  
Vol 8 ◽  
pp. 2207-2213 ◽  
Author(s):  
Tsutomu Konno ◽  
Misato Kishi ◽  
Takashi Ishihara
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Good Substrate ◽  
Excellent Yield ◽  
Cross Coupling Reaction ◽  
Stereocontrolled Synthesis ◽  
Excess Amount ◽  
High Yields ◽  
Vinyl Iodides

Treatment of readily prepared (Z)-6-benzyloxy-1,1,1,2-tetrafluoro-6-methyl-2-hepten-4-yne with 1.5 equiv of LHMDS in −78 °C for 1 h gave the corresponding trifluoromethylated diyne in an excellent yield. This diyne was found to be a good substrate for the carbocupration with various higher-ordered cyanocuprates to give the corresponding vinylcuprates in a highly regio- and stereoselective manner. The in situ generated vinylcuprates could react very smoothly with an excess amount of iodine, the vinyl iodides being obtained in high yields. Thus-obtained iodides underwent a very smooth Sonogashira cross-coupling reaction to afford various trans-enediynes in high yields.

Ferromagnetic Chain Based on Verdazyl-Nitroxide Diradical

2020 ◽  
Author(s):  
Evgeny Tretyakov ◽  
Svetlana Zhivetyeva ◽  
Pavel Petunin ◽  
Dmitry Gorbunov ◽  
Nina Gritsan ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Ferromagnetic Coupling ◽  
Nitronyl Nitroxide ◽  
Triplet Ground State ◽  
One Dimensional ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
Ferromagnetic Chain ◽  
High Yields

<p>Verdazyl-nitroxide diradicals were synthesized using the palladium-catalyzed cross-coupling reaction of the corresponding iodoverdazyls with a nitronyl nitroxide-2-ide gold(I) complex with high yields (up to 82%). The synthesized diradicals were found to be highly thermally stable and have a singlet (D<i>E</i><sub>ST</sub> » -64 cm<sup>–1</sup>) or triplet ground state (D<i>E</i><sub>ST</sub> ³ 25 and 100 cm<sup>–1</sup>), depending on which canonical hydrocarbon diradical type they belong to. Upon crystallization, triplet diradicals form unique one-dimensional (1D) spin <i>S</i> = 1 chains of organic diradicals with intrachain ferromagnetic coupling of <i>J</i>′/<i>k</i><sub>B</sub> from 3 to 6 K.</p>

An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction

2020 ◽  
Author(s):  
Chet Tyrol ◽  
Nang Yone ◽  
Connor Gallin ◽  
Jeffery Byers
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Radical Intermediates ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Boronic Esters ◽  
Carbon Centered Radical ◽  
Iron Based ◽  
High Yields

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.

scholarly journals Efficient in situ N-heterocyclic carbene palladium(ii) generated from Pd(OAc)2 catalysts for carbonylative Suzuki coupling reactions of arylboronic acids with 2-bromopyridine under inert conditions leading to unsymmetrical arylpyridine ketones: synthesis, characterization and cytotoxic activities

RSC Advances ◽  
2018 ◽  
Vol 8 (70) ◽  
pp. 40000-40015 ◽  
Author(s):  
Nedra Touj ◽  
Abdullah S. Al-Ayed ◽  
Mathieu Sauthier ◽  
Lamjed Mansour ◽  
Abdel Halim Harrath ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Suzuki Coupling ◽  
Boronic Acids ◽  
Cytotoxic Activities ◽  
Coupling Reactions ◽  
Component System ◽  
Arylboronic Acids ◽  
Cross Coupling Reaction

The in situ prepared four component system Pd(OAc)2, 1,3-dialkylbenzimidazolium halides 2a–i and 4a–i, K2CO3 under CO atmosphere catalyses carbonylative cross-coupling reaction of 2-bromopyridine with various boronic acids to yield unsymmetrical arylpyridine ketones.

Synthesis and Application of Tetrafluoroethylene (CF2CF2)-Containing Acetylene Derivatives

Synthesis ◽  
2020 ◽  
Vol 52 (13) ◽  
pp. 1947-1958
Author(s):  
Tsutomu Konno ◽  
Gen Egashira ◽  
Chihiro Kajimoto ◽  
Takuto Kataoka ◽  
Shigeyuki Yamada
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Alder Reaction ◽  
Diels Alder ◽  
Benzene Derivatives ◽  
Diels Alder Reaction ◽  
Cross Coupling Reaction ◽  
Oxidative Aromatization ◽  
High Yields ◽  
Acetylene Derivatives

On treating 1,3,4-tribromo-1,1,2,2-tetrafluorobutane, readily prepared from commercially available 4-bromo-3,3,4,4-tetrafluorobut-1-ene, with 3.3 equivalents of LHMDS at 0 °C in THF, the corresponding lithium acetylide could be prepared quantitatively. The acetylide reacted well with various aldehydes, ketones, or chlorosilanes to give the corresponding acetylene derivatives in high yields. It was also found that various iodoarenes could participate in the cross-coupling reaction with the zinc acetylide, readily prepared from the lithium acetylide and ZnCl2·TMEDA complex, in the presence of Pd(PPh3)4 to bring about the adducts in high yields. Thus-obtained acetylene derivatives underwent smooth Diels–Alder reaction with various 1,3-dienes to afford the corresponding 1,4- or 1,3-cyclohexadiene derivatives. In addition, it was revealed that the oxidative aromatization of the resulting cyclohexadiene derivatives with DDQ took place very smoothly, providing the multi-substituted benzene derivatives having a tetrafluoro­ethylene group.

Regiospecific Palladium-Catalyzed Cross-Coupling Reactions Using the Operational Equivalent of 1,3-Dilithiopropyne

Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2387-2394 ◽  
Author(s):  
Jorge A. Cabezas ◽  
Natasha Ferllini
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Terminal Alkyne ◽  
Copper Iodide ◽  
Reaction Conditions ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
High Yields

A regiospecific palladium-catalyzed cross-coupling reaction using the operational equivalent of the dianion 1,3-dilithiopropyne, with aromatic iodides is reported. This reaction gives high yields of 1-propyn-1-yl-benzenes and 2-(propyn-1-yl)thiophenes in the presence of catalytic amounts of palladium(0) or (II) and stoichiometric amounts of copper iodide. No terminal alkyne or allene isomers were detected. Reaction conditions were very mild and several functional groups were tolerated.

scholarly journals A urea-modified tryptophan basedin situreducing and stabilizing agent for the fabrication of gold nanoparticles as a Suzuki–Miyaura cross-coupling catalyst in water

2019 ◽  
Vol 1 (4) ◽  
pp. 1380-1386 ◽  
Author(s):  
Supriya Sasmal ◽  
Mintu Debnath ◽  
Sujay Kumar Nandi ◽  
Debasish Haldar
Keyword(s):  
Gold Nanoparticles ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Stabilizing Agent ◽  
Cross Coupling Reaction ◽  
Reaction In Water

Urea modified tryptophan has been used as anin situreducing and stabilizing agent for the fabrication of gold nanoparticles and the gold nanoparticles efficiently catalyzed the Suzuki–Miyaura cross-coupling reaction in water.

Analysis of the water extract of waste papaya bark ash and its implications as an in situ base in the ligand-free recyclable Suzuki–Miyaura coupling reaction

RSC Advances ◽  
2016 ◽  
Vol 6 (34) ◽  
pp. 28981-28985 ◽  
Author(s):  
Manashi Sarmah ◽  
Anindita Dewan ◽  
Manoj Mondal ◽  
Ashim J. Thakur ◽  
Utpal Bora
Keyword(s):  
Room Temperature ◽  
Water Extract ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Basic Medium ◽  
Low Temperature Combustion ◽  
Cross Coupling Reaction ◽  
Ligand Free ◽  
Temperature Combustion

The conversion of waste papaya-bark to ash–water extract via low-temperature combustion, and its utilization as an efficient and eco-friendly in situ basic medium for Suzuki–Miyaura cross-coupling reaction at room temperature are reported.

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