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Yakhvarov, Dmitry G.; Samieva, E. G.; Tazeev, D. I.; Budnikova, Yu. G.

doi:10.1023/a:1016024531639

Cited by 16 publications

(6 citation statements)

References 4 publications

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“…The single ortho- substituent 29 on 2-bromotoluene does not inhibit formation of 3f , but 2-bromomesitylene failed to react even under more forcing conditions (80 °C for 3 days), consistent with reports by Klein and others. 30 This result could reflect the high stability of (diamine)Ni(Br)(mesityl) complexes and/or the slow oxidative addition of 2-bromomesiltylene to our nickel catalyst. Alkyl bromides with β - branching couple well ( 3g ), but neopentyl bromide gave only trace product.…”

Section: Resultsmentioning

confidence: 95%

Replacing Conventional Carbon Nucleophiles with Electrophiles: Nickel-Catalyzed Reductive Alkylation of Aryl Bromides and Chlorides

2012

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A general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (−OH, −NHTs, −OAc, −OTs, −OTf, −COMe, −NHBoc, −NHCbz, −CN, −SO2Me), and the reactions are assembled on the benchtop with no special precautions to exclude air or moisture. The reaction displays different chemoselectivity than conventional cross-coupling reactions, such as the Suzuki–Miyaura, Stille, and Hiyama–Denmark reactions. Substrates bearing both an electrophilic and nucleophilic carbon result in selective coupling at the electrophilic carbon (R–X) and no reaction at the nucleophilic carbon (R–[M]) for organoboron (−Bpin), organotin (−SnMe3), and organosilicon (−SiMe2OH) containing organic halides (X–R–[M]). A Hammett study showed a linear correlation of σ and σ(−) parameters with the relative rate of reaction of substituted aryl bromides with bromoalkanes. The small ρ values for these correlations (1.2–1.7) indicate that oxidative addition of the bromoarene is not the turnover-frequency determining step. The rate of reaction has a positive dependence on the concentration of alkyl bromide and catalyst, no dependence upon the amount of zinc (reducing agent), and an inverse dependence upon aryl halide concentration. These results and studies with an organic reductant (TDAE) argue against the intermediacy of organozinc reagents.

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Section: Resultsmentioning

confidence: 95%

Replacing Conventional Carbon Nucleophiles with Electrophiles: Nickel-Catalyzed Reductive Alkylation of Aryl Bromides and Chlorides

2012

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“…The mechanism of electrochemical reduction of the starting [NiBr 2 (bpy) 2 ] complex 157 and the chemical reactivity of electrochemically generated nickel(0) bpy species toward organic halides have been described in detail earlier. 19 The reduction of the [NiBr 2 (bpy) 2 ] complex is realized as two consecutive quasi-reversible stages of the transfer of two electrons and then one electron. The first stage includes electrochemical reduction of the [NiBr 2 (bpy) 2 ] complex to [Ni 0 (bpy) 2 ] at E p C1 = −1.65 V (vs Ag/AgNO 3 , 0.01 M in CH 3 CN).…”

Section: ■ Preparation Of Organonickel Complexesmentioning

confidence: 99%

“…The first stable organonickel complexes bearing a Ni–C σ-bond were reported in the early 1960s, and derivatives containing the bpy ligand were described about 20 years later. , Chatt and Shaw had shown that ortho substituents in a σ-bonded aryl substituent can stabilize the complex by preventing free rotation about the nickel–carbon σ-bond. Since then, the synthesis and reactivity of σ-aryl–nickel complexes bearing diimine ligands have been the focus of several reports. − …”

Section: Introductionmentioning

confidence: 99%

Electrochemical Synthesis and Properties of Organonickel σ-Complexes

2014

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The organonickel complexes are organometallic compounds containing a Ni−C σ-bond (σ-complexes). These species are very reactive and have been mainly characterized as the intermediates of catalytic processes of cross coupling and homocoupling involving organic and elementoorganic substrates such as organic halides, chlorophosphines, unsaturated hydrocarbons, etc. Thus, only a limited number of these complexes have been isolated and characterized as the free stable species. Although the organonickel complexes have been known since the 1960s, the chemistry of these species is currently at the beginning stages of development. The interest of the researchers in this class of compounds has significantly increased over the past decade, resulting in a plethora of scientific papers published on this topic. At the same time, electrochemical methods have become more and more popular in modern synthetic chemistry, due to easy access to high reactive intermediates, including organometallic species, which can be selectively generated in situ and used for subsequent synthetic processes. This review summarizes the elaborated electrochemical approaches for the preparation of organonickel complexes, including a discussion of the important role of the electrochemical cell construction and the influence of the electrode material nature on the electrochemical process. In order to give more insight into the importance of organonickel complexes in synthetic chemistry and introduce the reader to this problem of organometallic chemistry, focused on the development of new synthetic protocols for preparation of stable organonickel complexes, an overview of the most important catalytic processes proceeding with participation of these highly reactive intermediates and the main types of organonickel complexes are presented. However, in this review organonickel complexes will be limited by examples in which the organic fragment is singly bonded to the nickel center, because these species are responsible for the catalytic reactions.

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“…The reference electrode is not connected to the power supply. 50 Chiba and co-workers used this setup for electrochemical cyanation of tertiary amines in order to avoid side reactions resulting from increasing potential. 51 Figure 2 also displays an example of a mediated CCE reaction: electrochemical iodination of methylarenes by N-hydroxyphthalimide (NHPI).…”

Section: Bulk Electrolysismentioning

confidence: 99%

“…The power supply applies the cell current, and the voltmeter is used to measure the potential of the working electrode against a reference electrode. The reference electrode is not connected to the power supply . Chiba and co-workers used this setup for electrochemical cyanation of tertiary amines in order to avoid side reactions resulting from increasing potential …”

Section: Bulk Electrolysismentioning

confidence: 99%

Constant Potential and Constant Current Electrolysis: An Introduction and Comparison of Different Techniques for Organic Electrosynthesis

et al. 2021

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Electrosynthesis involves transferring charge between two electrodes to promote chemical reactions by applying potential. The modes of controlling the current and potential can affect the reaction mechanism, product distribution and yields, and add a control factor for reaction optimization. In this Synopsis, theoretical discussion is applied to specific case studies from the literature to illustrate methods of adjusting and tracking electrical parameters for the optimization and monitoring of electroorganic reactions.

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Untitled

Cited by 16 publications

References 4 publications

Replacing Conventional Carbon Nucleophiles with Electrophiles: Nickel-Catalyzed Reductive Alkylation of Aryl Bromides and Chlorides

Replacing Conventional Carbon Nucleophiles with Electrophiles: Nickel-Catalyzed Reductive Alkylation of Aryl Bromides and Chlorides

Electrochemical Synthesis and Properties of Organonickel σ-Complexes

Constant Potential and Constant Current Electrolysis: An Introduction and Comparison of Different Techniques for Organic Electrosynthesis

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