Nickel-Catalyzed Heteroarenes Cross Coupling via Tandem C–H/C–O Activation
作者:Ting-Hsuan Wang、Ram Ambre、Qing Wang、Wei-Chih Lee、Pen-Cheng Wang、Yuhua Liu、Lili Zhao、Tiow-Gan Ong
DOI:10.1021/acscatal.8b03436
日期:2018.12.7
Inert aryl methyl ethers as coupling components via C–O activation have been established with a Ni catalyst for C–H activation of heteroarene. The key to simultaneous C–H/C–O bond activation is the use of sterically demanding o-tolylMgBr. The protocol is effective for a wide scope of substrates including naphthyl methyl ethers, anisoles, and a variety of other heteroarene derivatives. Detailed mechanistic
Transition‐Metal‐Free Oxidative Cross‐Coupling of Tetraarylborates to Biaryls Using Organic Oxidants
作者:Carolin Gerleve、Armido Studer
DOI:10.1002/anie.202002595
日期:2020.9
tetraarylborates undergo selective (cross)‐coupling through oxidation with Bobbitt's salt to give symmetric and unsymmetric biaryls. The organic oxoammonium salt can be used either as a stoichiometric oxidant or as a catalyst in combination with in situ generated NO2 and molecular oxygen as the terminal oxidant. For selected cases, oxidative coupling is also possible with NO2/O2 without any additional
容易制备的四芳基硼酸盐通过用博比特盐氧化进行选择性(交叉)偶联,得到对称和不对称的联芳基化合物。有机氧铵盐可用作化学计量氧化剂或与原位产生的NO 2和作为末端氧化剂的分子氧组合用作催化剂。对于某些情况,也可以使用 NO 2 /O 2进行氧化偶联,无需任何额外的氮氧自由基助催化剂。四芳基硼酸盐的无过渡金属催化氧化配体交叉偶联是前所未有的,所引入的方法提供了获得各种联芳基和杂联芳基系统的途径。
Ruthenium-Catalyzed Aromatization of Aromatic Enynes via the 1,2-Migration of Halo and Aryl Groups: A New Process Involving Electrocyclization and Skeletal Rearrangement
作者:Hung-Chin Shen、Sitaram Pal、Jian-Jou Lian、Rai-Shung Liu
DOI:10.1021/ja0379159
日期:2003.12.1
The halo and aryl substituents of the 1,2-disubstituted styryl group of aromatic enynes undergo a 1,2-shift in the aromatization reaction catalyzed by TpRuPPh3(CH3CN)2PF6 (10 mol %) in toluene (110 degrees C, 6-8 h). The aryl group shifts to the neighboring olefin carbon, and the iodo (or bromo) substituent migrates to the terminal alkyne carbon. The mechanisms of these two migrations have been elucidated
Nickel- or Iron-Catalyzed Cross-Coupling of Aryl Carbamates with Arylsilanes
作者:Wen-Juan Shi、Hong-Wei Zhao、Yang Wang、Zhi-Chao Cao、Li-Sheng Zhang、Da-Gang Yu、Zhang-Jie Shi
DOI:10.1002/adsc.201600590
日期:2016.7.28
Aryl carbamates were for the first time applied as electrophiles in the cross‐coupling with arylsilanes via nickel or iron catalysis to construct valuable biaryl compounds. This new coupling reaction features a good group tolerance and non‐sensitivity to steric hindrance on both aryl carbamates and arylsilanes.
Nickel Carbodicarbene Catalyzes Kumada Cross‐Coupling of Aryl Ethers with Grignard Reagents through C–O Bond Activation
作者:Ram Ambre、Hsuan Yang、Wen‐Ching Chen、Glenn P. A. Yap、Titel Jurca、Tiow‐Gan Ong
DOI:10.1002/ejic.201900692
日期:2019.8.15
The development of a cross‐couplingreaction protocol between aryl ethers and Grignard reagents catalyzed by carbodicarbene (CDC) nickel complexes to afford biaryl compounds through C–O cleavage is reported. Aromatic substrates featuring a broad range of electron neutral, donating, or withdrawinggroups are introduced at the desired position. The method has proven effective over a wide range of naphthyl