The coupling reaction of Grignard reagents with α,β-dibromoalkanes took place smoothly in THF/ HMPA (12:1) in the presence of a catalytic amount of copper(I) bromide and gave the products in 60–100% yields. Several α,ω-bis(vinylaryl)alkanes were prepared in reasonable yields by the application of this reaction.
The 11C-monomethylstannate prepared from [11C]-methyl iodide and Lappert's stannylene, was subject to a palladium-mediated cross-coupling reaction with an aryl halide under ligand-free conditions, to afford easily purified 11C-methyl(hetero)arenes in high radiochemical yields.
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。
Efficient phosphine ligands for the one-pot palladium-catalyzed borylation/Suzuki–Miyaura cross-coupling reaction
We report the synthesis of 2-(anthracen-9-yl)-1H-inden-3-yl dicyclohexylphosphine and its use in palladium-catalyzed borylation/Suzuki-Miyauracross-coupling reaction to prepare a variety of symmetrical and unsymmetrical biaryl compounds in excellent yield.