Nickel-Phosphine Complex-Catalyzed Grignard Coupling. I. Cross-Coupling of Alkyl, Aryl, and Alkenyl Grignard Reagents with Aryl and Alkenyl Halides: General Scope and Limitations
(s)), aryl, and alkenyl Grignard reagents and nonfused, fused, and substituted aromatic halides and haloolefins. Limitations lie in sluggish reactions between alkyl Grignard reagents and dihaloethylenes. The most effective catalysts are [Ni(C6H5)2P(CH2)3P(C6H5)2}Cl2] for alkyl and simple aryl Grignard reagents, [Ni(CH3)2P(CH2)2P(CH3)2}Cl2] for alkenyl and allylic Grignard reagents and [NiP(C6H5)3}2-Cl2]
已经确定,二卤代二膦镍 (II) 配合物对格氏试剂与芳基和链烯基卤化物的选择性交叉偶联表现出极高的催化活性。由于该催化反应程序简单、反应条件温和、偶联产物的收率和纯度高,以及广泛适用于涉及伯和仲烷基的反应(无论β-的存在与否),该催化反应可用于合成实践。氢 (s))、芳基和烯基格氏试剂以及非稠合、稠合和取代的芳族卤化物和卤代烯烃。限制在于烷基格氏试剂和二卤乙烯之间的缓慢反应。对于烷基和简单的芳基格氏试剂,最有效的催化剂是 [Ni(C6H5)2P(CH2)3P(C6H5)2}Cl2],[Ni(CH3)2P(CH2)2P(CH3)2}Cl2] 用于烯基和烯丙基格氏试剂,[NiP(C6H5)3}2-Cl2] 用于空间位阻芳基格氏试剂和卤化物。膦配体对...的巨大稳定作用
Alkylation‐Terminated Catellani Reactions Using Alkyl Carbagermatranes
Catellani reaction has received substantial attention because it enables rapid multiple derivatization on aromatics. While using alkyl electrophiles to achieve ortho‐alkylation was one of the earliest applications of the Catellani reaction, ipso‐alkylation‐terminated reactions with β‐H‐containing reactants has not been realized to date. Herein, we report alkylation‐terminated Catellani reaction using alkyl
Cyanophenylation of Aromatic Nitriles by Terephthalonitrile Dianion: Is the Charge-Transfer Complex a Key Intermediate?
作者:Elena V. Panteleeva、Lyudmila N. Shchegoleva、Viktor P. Vysotsky、Leonid M. Pokrovsky、Vitalij D. Shteingarts
DOI:10.1002/ejoc.200400851
日期:2005.6
The interaction of terephthalonitrile (1) dianion (12–) with benzonitrile (2) or m-tolunitrile (3) provides 4,4'-dicyanobiphenyl (4) or 4,4'-dicyano-2-methylbiphenyl (5), respectively. This result shows that dianion 12– serves as a reagent for p-cyanophenylation of aromatic nitriles. Based on experimental data, such as the chemical trapping of the 4,4'-dicyanobiphenyl precursor 4-cyano-1-(p-cyanophenyl)cyclohexa-2
Novel Homologation Reaction of Arylzincates Bearing a Leaving Group at the Ortho and Meta Positions
作者:Toshiro Harada、Minako Chiba、Akira Oku
DOI:10.1021/jo990937m
日期:1999.10.1
Arylzincates bearing a leaving group at the ortho, meta, and para positions were generated by iodine/zinc exchange reaction of the corresponding iodoaryl sulfonates with Bu(3)ZnLi, and their reactivity was investigated via product analysis after hydrolysis and treatment with iodine. Zincates derived from o-iodophenyl triflates and tosylate underwent homologation reaction to give o-butylphenylzinc species
Nickel-on-Charcoal-Catalyzed Aromatic Aminations and Kumada Couplings: Mechanistic and Synthetic Aspects
作者:Stefan Tasler、Bruce H. Lipshutz
DOI:10.1021/jo020297e
日期:2003.2.1
nickel-on-charcoal (Ni/C) have been revised, making them simpler and more time efficient. For both types of reactions, reduction of the catalyst precursor Ni(II)/C using n-BuLi prior to addition of a substrate can be avoided. Instead, in amination reactions, the amine in combination with lithium tert-butoxide was found to convert Ni(II)/C to active Ni(0). For Kumada couplings, direct reduction of Ni(II)/C by the Grignard