Mild and Efficient Nickel-Catalyzed Heck Reactions with Electron-Rich Olefins
作者:Thomas M. Gøgsig、Jonatan Kleimark、Sten O. Nilsson Lill、Signe Korsager、Anders T. Lindhardt、Per-Ola Norrby、Troels Skrydstrup
DOI:10.1021/ja2084509
日期:2012.1.11
A new efficient protocol for the nickel-catalyzed Heckreaction of aryl triflates with vinyl ethers is presented. Mild reaction conditions that equal those of the corresponding palladium-catalyzed Heckreaction are applied, representing a practical and more sustainable alternative to the conventional regioselective arylation of vinyl ethers. A catalytic system comprised of Ni(COD)(2) and 1,1'-bis(
Ni-Catalyzed Cross-Electrophile Coupling of Aryl Triflates with Thiocarbonates via C–O/C–O Bond Cleavage
作者:Zhaodong Zhu、Yuxin Gong、Weiqi Tong、Weichao Xue、Hegui Gong
DOI:10.1021/acs.orglett.1c00313
日期:2021.3.19
A nickel-catalyzed reductive coupling of aryl triflates with thiocarbonates is reported here. Both electron-rich and -deficient aryl C(sp2)–O electrophiles as well as a class of O-tBu S-alkyl thiocarbonates are compatible with the optimized reaction conditions, as evidenced by 49 examples. The reaction also proceeds with good chemoselective cleavage of the C–O bond with regard to thioesters. This work
此处报道了芳基三氟甲磺酸酯与硫代碳酸酯的镍催化还原偶联。富电子和不足的芳基C(sp 2)-O亲电体以及一类O - t Bu S-烷基硫代碳酸酯都与优化的反应条件兼容,如49个实例所示。对于硫代酯,该反应还会以良好的C–O键化学选择性裂解来进行。这项工作拓宽了镍催化的还原交叉亲电子偶联反应的范围。
Ketone Synthesis by a Nickel-Catalyzed Dehydrogenative Cross-Coupling of Primary Alcohols
作者:Thomas Verheyen、Lars van Turnhout、Jaya Kishore Vandavasi、Eric S. Isbrandt、Wim M. De Borggraeve、Stephen G. Newman
DOI:10.1021/jacs.9b03280
日期:2019.5.1
intermolecular coupling of primaryalcohols and organotriflates has been developed to provide ketones by the action of a Ni(0) catalyst. This oxidative transformation is proposed to occur by the union of three distinct catalytic cycles. Two competitive oxidation processes generate aldehyde in situ via hydrogentransfer oxidation or (pseudo)dehalogenation pathways. As aldehyde forms, a Ni-catalyzed carbonyl-Heck
under the Pd/C-catalyzed hydrogenation conditions in the presence of diethylamine and the method could also be applicable to the hydrodeoxygenation of morphine to afford 3-deoxy-7,8-dihydromorphine. Diethylamine is not only a scavenger of the corresponding methanesulfonic acid derivative, which is produced during the reaction progress, but also a strong promoter of the Pd/C-catalyzedreduction of aryl
A Pd/C-catalyzed deoxygenationmethod of phenolic hydroxyl groups via aryl triflates or mesylates using Mg metal in MeOH at room temperature was developed. The addition of NH4OAc dramatically affects the reactivity and reaction rate. This method is particularly attractive to provide an environmentally benign and widely applicable removal method of phenolic alcohols under quite mild reaction conditions