Copper-catalysed cross-coupling of alkyl Grignard reagents and propargylic ammonium salts: stereospecific synthesis of allenes

2018 ◽  
Vol 54 (60) ◽  
pp. 8343-8346 ◽  
Author(s):  
Manuel Guisán-Ceinos ◽  
Victor Martín-Heras ◽  
Rita Soler-Yanes ◽  
Diego J. Cárdenas ◽  
Mariola Tortosa
Keyword(s):  
Convenient Method ◽  
Cross Coupling ◽  
Ammonium Salts ◽  
Stereospecific Synthesis ◽  
Grignard Reagents ◽  
Chirality Transfer ◽  
High Yields

A robust and convenient method to prepare enantiomerically enriched allenes using propargylic salts is reported. High yields and excellent chirality transfer are observed.

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>

Fe-Catalyzed Conjunctive Cross-Couplings of Unactivated Alkenes with Grignard Reagents

2020 ◽  
Author(s):  
Lei Liu ◽  
Wes Lee ◽  
Cassandra R. Youshaw ◽  
Mingbin Yuan ◽  
Michael B. Geherty ◽  
...  
Keyword(s):  
Functional Groups ◽  
Cross Coupling ◽  
Alkyl Halides ◽  
Grignard Reagents ◽  
Turnover Frequency ◽  
Diverse Range ◽  
Cascade Cyclization ◽  
Radical Cascade

The first iron-catalyzed three-component cross-coupling of unactivated olefins with alkyl halides and Grignard reagents is reported. The reaction operates under fast turnover frequency and tolerates a diverse range of sp2-hybridized nucleophiles, alkyl halides, and unactivated olefins bearing diverse functional groups to yield the desired 1,2-alkylarylated products with high regiocontrol. Further, we demonstrate that this protocol is amenable for the synthesis of new (hetero)carbocycles including tetrahydrofurans and pyrrolidines via a three-component radical cascade cyclization/arylation that forges three new C-C bonds.

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.

Design and Development of Fe-Catalyzed Intra- and Intermolecular Carbofunctionalization of Vinyl Cyclopropanes

2019 ◽  
Author(s):  
Lei Liu ◽  
Wes Lee ◽  
Mingbin Yuan ◽  
Chris Acha ◽  
Michael B. Geherty ◽  
...  
Keyword(s):  
Bond Formation ◽  
Cross Coupling ◽  
Alkyl Halides ◽  
Grignard Reagents ◽  
Mechanistic Studies ◽  
Radical Intermediates ◽  
Design And Implementation ◽  
Solvent Cage ◽  
Radical Cascade ◽  
Radical Processes

Design and implementation of the first (asymmetric) Fe-catalyzed intra- and intermolecular difunctionalization of vinyl cyclopropanes (VCPs) with alkyl halides and aryl Grignard reagents has been realized via a mechanistically driven approach. Mechanistic studies support the diffusion of the alkyl radical intermediates out of the solvent cage to participate in an intra- or -intermolecular radical cascade with the VCP followed by re-entering the Fe radical cross-coupling cycle to undergo selective C(sp2)-C(sp3) bond formation. Overall, we provide new design principles for Fe-mediated radical processes and underscore the potential of using combined computations and experiments to accelerate the development of challenging transformations.

Novel cross-coupling reactions between organotellurides and Grignard reagents employing a MnCl2/CuI catalytic system

2012 ◽  
Vol 53 (28) ◽  
pp. 3556-3559 ◽  
Author(s):  
Marcio S. Silva ◽  
Renan S. Ferrarini ◽  
Bruno A. Sousa ◽  
Fabiano T. Toledo ◽  
João V. Comasseto ◽  
...  
Keyword(s):  
Catalytic System ◽  
Cross Coupling ◽  
Grignard Reagents ◽  
Coupling Reactions ◽  
Cross Coupling Reactions
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