scholarly journals Photoinduced Nickel-Catalyzed Deaminative Cross-Electrophile Coupling

2021 ◽  
Author(s):  
Tao Yang ◽  
Yi Wei ◽  
Ming Joo Koh
Keyword(s):  
Electron Transfer ◽  
Bond Formation ◽  
Cross Coupling ◽  
Alkyl Halides ◽  
Single Electron Transfer ◽  
Alkyl Radicals ◽  
Carbon Carbon Bonds ◽  
Simple Protocol ◽  
Donor Acceptor ◽  
Site Selective

<div>The construction of carbon-carbon bonds through cross-coupling between two electrophiles in the absence of excess metallic reducing agents is a desirable objective in chemistry. Here, we show that <i>N</i>-alkylpyridinium salts can be efficiently merged with aryl or alkyl halides in an intermolecular fashion, affording products in up to 90%</div><div>yield at ambient temperature. These reactions harness the ability of <i>N</i>-alkylpyridinium salts to form electron donor-acceptor complexes with Hantzsch esters, enabling photoinduced single-electron transfer and fragmentation to afford alkyl radicals that are subsequently trapped by a Ni-based catalytic species to promote C(sp<sup>2</sup>)-C(sp<sup>3</sup>) and</div><div>C(sp<sup>3</sup>)-C(sp<sup>3</sup>) bond formation. The operationally simple protocol is applicable to site-selective cross-coupling and tolerates diverse functional groups, including those that are sensitive towards metal reductants.</div>

scholarly journals Photoinduced Nickel-Catalyzed Deaminative Cross-Electrophile Coupling

2021 ◽  
Author(s):  
Tao Yang ◽  
Yi Wei ◽  
Ming Joo Koh
Keyword(s):  
Electron Transfer ◽  
Bond Formation ◽  
Cross Coupling ◽  
Alkyl Halides ◽  
Single Electron Transfer ◽  
Alkyl Radicals ◽  
Carbon Carbon Bonds ◽  
Simple Protocol ◽  
Donor Acceptor ◽  
Site Selective

<div>The construction of carbon-carbon bonds through cross-coupling between two electrophiles in the absence of excess metallic reducing agents is a desirable objective in chemistry. Here, we show that <i>N</i>-alkylpyridinium salts can be efficiently merged with aryl or alkyl halides in an intermolecular fashion, affording products in up to 90%</div><div>yield at ambient temperature. These reactions harness the ability of <i>N</i>-alkylpyridinium salts to form electron donor-acceptor complexes with Hantzsch esters, enabling photoinduced single-electron transfer and fragmentation to afford alkyl radicals that are subsequently trapped by a Ni-based catalytic species to promote C(sp<sup>2</sup>)-C(sp<sup>3</sup>) and</div><div>C(sp<sup>3</sup>)-C(sp<sup>3</sup>) bond formation. The operationally simple protocol is applicable to site-selective cross-coupling and tolerates diverse functional groups, including those that are sensitive towards metal reductants.</div>

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.

Recent Advances in C–Br Bond Formation

Synlett ◽  
2021 ◽  
Author(s):  
Ying-Yeung Yeung ◽  
Jonathan Wong
Keyword(s):  
Organic Synthesis ◽  
Aromatic Compounds ◽  
Bond Formation ◽  
Cross Coupling ◽  
Catalytic Site ◽  
Atom Transfer ◽  
Bond Forming ◽  
Recent Advances ◽  
Catalytic Asymmetric ◽  
Site Selective

AbstractOrganobromine compounds are extremely useful in organic synthesis. In this perspective, a focused discussion on some recent advancements in C–Br bond-forming reactions is presented.1 Introduction2 Selected Recent Advances2.1 Catalytic Asymmetric Bromopolycyclization of Olefinic Substrates2.2 Catalytic Asymmetric Intermolecular Bromination2.3 Some New Catalysts and Reagents for Bromination2.4 Catalytic Site-Selective Bromination of Aromatic Compounds2.5 sp3 C–H Bromination via Atom Transfer/Cross-Coupling3 Outlook

Evidence for single electron transfer in the reaction of alkoxides with alkyl halides

1984 ◽  
Vol 25 (45) ◽  
pp. 5107-5110 ◽  
Author(s):  
E.C. Ashby ◽  
Dong-Hak Bae ◽  
Won-Suh Park ◽  
Robert N. Depriest ◽  
Wei-Yang Su
Keyword(s):  
Electron Transfer ◽  
Alkyl Halides ◽  
Single Electron ◽  
Single Electron Transfer

scholarly journals Ni/Co-Catalyzed Homo-Coupling of Alkyl Tosylates

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1458 ◽  
Author(s):  
Kimihiro Komeyama ◽  
Ryusuke Tsunemitsu ◽  
Takuya Michiyuki ◽  
Hiroto Yoshida ◽  
Itaru Osaka
Keyword(s):  
Electron Transfer ◽  
Oxidative Addition ◽  
Alkyl Halides ◽  
Cobalt Catalysts ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Mild Conditions

A direct reductive homo-coupling of alkyl tosylates has been developed by employing a combination of nickel and nucleophilic cobalt catalysts. A single-electron-transfer-type oxidative addition is a pivotal process in the well-established nickel-catalyzed coupling of alkyl halides. However, the method cannot be applied to the homo-coupling of ubiquitous alkyl tosylates due to the high-lying σ*(C–O) orbital of the tosylates. This paper describes a Ni/Co-catalyzed protocol for the activation of alkyl tosylates on the construction of alkyl dimers under mild conditions.

scholarly journals Alcohol-Initiated Dediazoniation of Aryldiazonium Ions to Aryl Radicals: A Simple and Efficient Route to Arylboronates

2018 ◽  
Vol 42 (9) ◽  
pp. 481-485
Author(s):  
Xiulian Zhang ◽  
Zhicheng Zhang ◽  
Yongbin Xie ◽  
Yujie Jiang ◽  
Ruibo Xu ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Bond Formation ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Aryl Radical ◽  
Radical Species ◽  
Aryl Radicals ◽  
Efficient Access ◽  
Efficient Route ◽  
Operational Simplicity

A simple and efficient access to arylboronates was achieved with methanol-initiated borylation of aryldiazonium salts. Reduction of aryldiazonium ions by single electron transfer from methanol affords aryl radical species, which undergo a subsequent C–B bond formation with bis(pinacolato)diboron. This highly practical borylation process, which can be carried out on the gram-scale, enjoys operational simplicity as well as mild and catalyst-free conditions.

Microfluidic electrochemistry for single-electron transfer redox-neutral reactions

Science ◽  
2020 ◽  
Vol 368 (6497) ◽  
pp. 1352-1357 ◽  
Author(s):  
Yiming Mo ◽  
Zhaohong Lu ◽  
Girish Rughoobur ◽  
Prashant Patil ◽  
Neil Gershenfeld ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Molecular Diffusion ◽  
Microfluidic Channel ◽  
Cross Coupling ◽  
Reactive Intermediates ◽  
Single Electron ◽  
Visible Light Photocatalysis ◽  
Single Electron Transfer ◽  
Selective Transformation ◽  
Crystal Compound

Electrochemistry offers opportunities to promote single-electron transfer (SET) redox-neutral chemistries similar to those recently discovered using visible-light photocatalysis but without the use of an expensive photocatalyst. Herein, we introduce a microfluidic redox-neutral electrochemistry (μRN-eChem) platform that has broad applicability to SET chemistry, including radical-radical cross-coupling, Minisci-type reactions, and nickel-catalyzed C(sp2)–O cross-coupling. The cathode and anode simultaneously generate the corresponding reactive intermediates, and selective transformation is facilitated by the rapid molecular diffusion across a microfluidic channel that outpaces the decomposition of the intermediates. μRN-eChem was shown to enable a two-step gram-scale electrosynthesis of a nematic liquid crystal compound, demonstrating its practicality.

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