Construction of Electrocatalytic Electrodes Bearing the Triphenylamine Nucleus Covalently Bound to Carbon. A Halogen Dance in Protonated Aminotriphenylamines
摘要:
The triarylamine nucleus has been attached to a carbon fiber electrode by diazotization of an aminotriphenylamine followed by electrochemical reduction. The resulting electrodes can electrocatalyze the oxidation of organic substrates. In acid, 4-amino-4',4 ''-dibromotriphenylamine undergoes dismutation into a mixture of amines containing from 0 to 3 bromine atoms.
Synthesis of Enantioenriched Allylic Silanes via Nickel-Catalyzed Reductive Cross-Coupling
作者:Julie L. Hofstra、Alan H. Cherney、Ciara M. Ordner、Sarah E. Reisman
DOI:10.1021/jacs.7b11707
日期:2018.1.10
asymmetric Ni-catalyzed reductive cross-coupling has been developed to prepare enantioenriched allylic silanes. This enantioselective reductive alkenylation proceeds under mild conditions and exhibits good functional group tolerance. The chiral allylic silanes prepared here undergo a variety of stereospecific transformations, including intramolecular Hosomi-Sakurai reactions, to set vicinal stereogenic centers
已开发出不对称 Ni 催化的还原交叉偶联来制备对映体富集的烯丙基硅烷。这种对映选择性还原烯基化在温和条件下进行,并表现出良好的官能团耐受性。这里制备的手性烯丙基硅烷经过各种立体定向转化,包括分子内细美-樱井反应,以设置具有优异手性转移的邻位立体中心。
Unprecedented McMurry Reactions with Acylsilanes: Enedisilane Formation versus Brook Rearrangement
The first inter- and intramolecular McMurry reactions of aroyltrimethylsilanes to substituted 1,2-bis(trimethylsilyl)ethene derivatives 2a-c and 7 are described. A low-valenttitanium reagent prepared by the reduction of TiCl3 with Na on inorganic supports (Al2O3, NaCl, TiO2) turned out to be best suited. Depending on the reaction conditions and on the particular substitution patterns of the substrates
描述了芳基三甲基硅烷与取代的1,2-双(三甲基甲硅烷基)乙烯衍生物2a-c和7的第一分子间和分子内McMurry反应。事实证明,通过在无机载体(Al 2 O 3,NaCl,TiO 2)上用Na还原TiCl 3制备的低价钛试剂是最合适的。根据反应条件和底物的特定取代方式,导致形成C,O-二甲硅烷基烯醇醚的中间体1,2-二甲硅烷基化的1,2-二醇钛酸酯的Brook重排可能与McMurry竞争脱氧途径。