2189-60-8Relevant articles and documents
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Petrow,Laptewa,Ptschelkina
, (1945)
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Ligand redox effects in the synthesis, electronic structure, and reactivity of an alkyl-alkyl cross-coupling catalyst
Jones, Gavin D.,Martin, Jason L.,McFarland, Chris,Allen, Olivia R.,Hall, Ryan E.,Haley, Aireal D.,Brandon, R. Jacob,Konovalova, Tatyana,Desrochers, Patrick J.,Pulay, Peter,Vicic, David A.
, p. 13175 - 13183 (2006)
The ability of the terpyridine ligand to stabilize alkyl complexes of nickel has been central in obtaining a fundamental understanding of the key processes involved in alkyl-alkyl cross-coupling reactions. Here, mechanistic studies using isotopically labeled (TMEDA)NiMe2 (TMEDA = N,N,N′,N′-tetramethylethylenediamine) have shown that an important catalyst in alkyl-alkyl cross-coupling reactions, (tpy′)NiMe (2b, tpy′ = 4,4′,4″-tri-tert-butylterpyridine), is not produced via a mechanism that involves the formation of methyl radicals. Instead, it is proposed that (terpyridine)NiMe complexes arise via a comproportionation reaction between a Ni(II)-dimethyl species and a Ni(0) fragment in solution upon addition of a terpyridine ligand to (TMEDA)NiMe2. EPR and DFT studies on the paramagnetic (terpyridine)NiMe (2a) both suggest that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand. Thus, an important consequence of these results is that alkyl halide reduction by (terpyridine)NiRalkyl complexes appears to be substantially ligand based. A comprehensive survey investigating the catalytic reactivity of related ligand derivatives suggests that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors.
Cobalt(II) complexes bearing a bulky N-heterocyclic carbene for catalysis of Kumada-Tamao-Corriu cross-coupling reactions of aryl halides
Matsubara, Kouki,Sueyasu, Tsukasa,Esaki, Mariko,Kumamoto, Aya,Nagao, Shinya,Yamamoto, Hitomi,Koga, Yuji,Kawata, Satoshi,Matsumoto, Taisuke
, p. 3079 - 3086 (2012)
Cobalt(II) iodide, bromide, and chloride react with 1 equiv. of IPr [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene] to form a series of tetrahedral dimeric (30e) complexes of cobalt(II) in good yields. These were transformed into the monomeric forms in the presence of pyridine. These complexes were characterized by SQUID, XPS, UV/Vis spectroscopy, elemental analysis, and X-ray crystallography, and were found to have high catalytic activity for Kumada-Tamao-Corriu cross-coupling reactions of aryl halides. Copyright
Palladium and Nickel Catalyzed Suzuki Cross-Coupling with Alkyl Fluorides
Balaraman, Kaluvu,Wolf, Christian
supporting information, p. 8994 - 8999 (2021/11/20)
Suzuki cross-coupling of benzylic and unactivated aliphatic fluorides with aryl- and alkenylboronic acids has been achieved via mechanistically distinct Pd and Ni catalyzed pathways that outperform competing protodeboronation, β-hydride elimination, and h
A visible-light mediated ring opening reaction of alkylidenecyclopropanes for the generation of homopropargyl radicals
Mao, Ben,Ning, Chao,Shi, Min,Wei, Yin,Zhang, Xiao-Yu
, p. 9088 - 9095 (2021/07/12)
Classical cyclopropylcarbinyl radical clock reactions have been widely applied to conduct mechanistic studies for probing radical processes for a long time; however, alkylidenecyclopropanes, which have a similar molecular structure to methylcyclopropanes, surprisingly have not yet attracted researcher's attention for similar ring opening radical clock processes. In recent years, photocatalytic NHPI ester activation chemistry has witnessed significant blooming developments and provided new synthetic routes for cross-coupling reactions. Herein, we wish to report a non-classical ring opening radical clock reaction using innovative NHPI esters bearing alkylidenecyclopropanes upon photoredox catalysis, providing a brand-new synthetic approach for the direct preparation of a variety of alkynyl derivatives. The potential synthetic utility of this protocol is demonstrated in the diverse transformations and facile synthesis of bioactive molecules or their derivatives and medicinal substances.
