254454-47-2Relevant academic research and scientific papers
Enantioselective Conjugate Addition of Stabilized Arylzinc Iodide to Enones: an Improved Protocol of the Hayashi Reaction
Casotti, Gianluca,Rositano, Vincenzo,Iuliano, Anna
, p. 1126 - 1131 (2020/12/17)
Stabilised arylzinc iodide, prepared by direct insertion of zinc into aryl iodides, were used as nucleophiles in the Hayashi Rh-catalysed enantioselective conjugate addition to enones. The reaction conditions were optimized in the addition of phenylzinc i
Rhodium-Catalyzed Addition of Organozinc Iodides to Carbon-11 Isocyanates
Fouad, Moustafa H.,Ismailani, Uzair S.,Mair, Braeden A.,Munch, Maxime,Rotstein, Benjamin H.
supporting information, p. 2746 - 2750 (2020/04/16)
Amides were prepared using rhodium-catalyzed coupling of organozinc iodides and carbon-11 (11C, t1/2 = 20.4 min) isocyanates. Nonradioactive isocyanates and sp3 or sp2 organozinc iodides generated amides in yields of 13%-87%. Incorporation of cyclotron-produced [11C]CO2 into 11C-amide products proceeded in yields of 5%-99%. The synthetic utility of the methodology was demonstrated through the isolation of [11C]N-(4-fluorophenyl)-4-methoxybenzamide ([11C]6g) with a molar activity of 267 GBq μmol-1 and 12% radiochemical yield in 21 min from the beginning of synthesis.
Arylzinc Halides by Silver Catalyzed Zinc Insertion into Aryl Iodides
Casotti, Gianluca,Iuliano, Anna,Carpita, Adriano
, p. 1021 - 1026 (2019/01/04)
A catalytic amount of silver acetate efficiently promotes direct insertion of zinc metal into aryl iodides, having different structure, in ethereal solvent. Electron-rich substrates also rapidly undergo oxidative metalation. The arylzinc iodides formed give Negishi coupling products under mild reaction conditions to obtain biaryls in high yields. Sensitive functional groups like aldehydes and primary amides are well-tolerated.
Mechanochemical Activation of Zinc and Application to Negishi Cross-Coupling
Cao, Qun,Howard, Joseph L.,Wheatley, Emilie,Browne, Duncan L.
supporting information, p. 11339 - 11343 (2018/08/28)
A form independent activation of zinc, concomitant generation of organozinc species and engagement in a Negishi cross-coupling reaction via mechanochemical methods is reported. The reported method exhibits a broad substrate scope for both C(sp3)–C(sp2) and C(sp2)–C(sp2) couplings and is tolerant to many important functional groups. The method may offer broad reaching opportunities for the in situ generation organometallic compounds from base metals and their concomitant engagement in synthetic reactions via mechanochemical methods.
Ni-Catalyzed Regioselective Alkylarylation of Vinylarenes via C(sp3)-C(sp3)/C(sp3)-C(sp2) Bond Formation and Mechanistic Studies
Kc, Shekhar,Dhungana, Roshan K.,Shrestha, Bijay,Thapa, Surendra,Khanal, Namrata,Basnet, Prakash,Lebrun, Robert W.,Giri, Ramesh
supporting information, p. 9801 - 9805 (2018/08/06)
We report a Ni-catalyzed regioselective alkylarylation of vinylarenes with alkyl halides and arylzinc reagents to generate 1,1-diarylalkanes. The reaction proceeds well with primary, secondary and tertiary alkyl halides, and electronically diverse arylzinc reagents. Mechanistic investigations by radical probes, competition studies and quantitative kinetics reveal that the current reaction proceeds via a Ni(0)/Ni(I)/Ni(II) catalytic cycle by a rate-limiting direct halogen atom abstraction via single electron transfer to alkyl halides by a Ni(0)-catalyst.
Ni-Catalyzed Regioselective Dicarbofunctionalization of Unactivated Olefins by Tandem Cyclization/Cross-Coupling and Application to the Concise Synthesis of Lignan Natural Products
Kc, Shekhar,Basnet, Prakash,Thapa, Surendra,Shrestha, Bijay,Giri, Ramesh
, p. 2920 - 2936 (2018/03/09)
We disclose a (terpy)NiBr2-catalyzed reaction protocol that regioselectively difunctionalizes unactivated olefins with tethered alkyl halides and arylzinc reagents. The reaction shows an excellent functional group tolerance (such as ketones, es
Synergistic Bimetallic Ni/Ag and Ni/Cu Catalysis for Regioselective γ,δ-Diarylation of Alkenyl Ketimines: Addressing β-H Elimination by in Situ Generation of Cationic Ni(II) Catalysts
Basnet, Prakash,Kc, Shekhar,Dhungana, Roshan K.,Shrestha, Bijay,Boyle, Timothy J.,Giri, Ramesh
supporting information, p. 15586 - 15590 (2018/11/23)
We disclose unprecedented synergistic bimetallic Ni/Ag and Ni/Cu catalysts for regioselective γ,δ-diarylation of unactivated alkenes in simple ketimines with aryl halides and arylzinc reagents. The bimetallic synergy, which generates cationic Ni(II) speci
Single-electron-transfer-induced coupling of arylzinc reagents with aryl and alkenyl halides
Shirakawa, Eiji,Tamakuni, Fumiko,Kusano, Eugene,Uchiyama, Nanase,Konagaya, Wataru,Watabe, Ryo,Hayashi, Tamio
supporting information, p. 521 - 525 (2014/01/23)
Arylzinc reagents, prepared from aryl halides/zinc powder or aryl Grignard reagents/zinc chloride, were found to undergo coupling with aryl and alkenyl halides without the aid of transition-metal catalysis to give biaryls and styrene derivatives, respectively. In this context, we have already reported the corresponding reaction using aryl Grignard reagents instead of arylzinc reagents. Compared with the Grignard cross-coupling, the present reaction features high functional-group tolerance, whereby electrophilic groups such as alkoxycarbonyl and cyano groups are compatible as substituents on both the arylzinc reagents and the aryl halides. Aryl halides receive a single electron and thereby become activated as the corresponding anion radicals, which react with arylzinc reagents, thus leading to the cross-coupling products. Arylzinc reagents were found to undergo coupling with aryl and alkenyl halides to give biaryl and styrene derivatives, respectively. The cross-coupling, which features high functional-group tolerance, proceeds through a single-electron-transfer mechanism and thus does not require the aid of transition-metal catalysis.
Negishi coupling reactions as a valuable tool for [11C]methyl- arene formation; First proof of principle
Kealey,Passchier,Huiban
supporting information, p. 11326 - 11328 (2013/12/04)
The Negishi coupling reaction between arylzinc halide reagents and 11CH3I has been used to synthesise 11C- methylated arene species via a palladium-mediated process. The metabotropic glutamate receptor subtype-5 radiotracer [11C]MPEP has been radiolabelled using this technique.
New chemical synthesis of functionalized arylzinc compounds from aromatic or thienyl bromides under mild conditions using a simple cobalt catalyst and zinc dust
Fillon, Hyacinthe,Gosmini, Corinne,Perichon, Jacques
, p. 3867 - 3870 (2007/10/03)
A new chemical method for the preparation of arylzinc intermediates is described in acetonitrile, on the basis of the activation of aryl bromides by low-valent cobalt species arising from the reduction of cobalt halide by zinc dust. This procedure allows for the synthesis of a variety of functionalized aryl- and thienylzinc species in good to excellent yields. The versatility and the simplicity of that original method represent an alternative to most known procedures.
