Regiocontrolled Cu<sup>I</sup>-Catalyzed Borylation of Propargylic-Functionalized Internal Alkynes
作者:Abraham L. Moure、Ramón Gómez Arrayás、Diego J. Cárdenas、Inés Alonso、Juan C. Carretero
DOI:10.1021/ja300627s
日期:2012.5.2
orbitalic influence from the propargylic group, matched with ligand and substrate size effects, as key factors involved in the high β-selectivity. The vinylboronates allowed the stereoselective synthesis of trisubstituted olefins, while allylic substitution of the SO(2)Py group without affecting the boronate group provided access to formal hydroboration products of unbiased dialkylalkynes.
Catalytic Activation of Diazo Compounds Using Electron-Rich, Defined Iron Complexes for Carbene-Transfer Reactions
作者:Michael S. Holzwarth、Isabel Alt、Bernd Plietker
DOI:10.1002/anie.201201409
日期:2012.5.29
transfer: The electron‐rich iron complex Bu4N[Fe(CO)3(NO)] efficientlycatalyzes different carbene‐transfer reactions. Various diazo compounds can be used. The high stability of the employed iron complexes is demonstrated by the generation of the diazo reagent in situ and a sequential iron‐catalyzed allylic sulfenylation/Doyle–Kirmse reaction.
碳转移:富电子的铁络合物Bu 4 N [Fe(CO)3(NO)]有效催化不同的卡宾转移反应。可以使用各种重氮化合物。重氮试剂的原位生成和连续的铁催化的烯丙基亚磺酰化/道尔-柯尔姆斯反应证明了所用铁配合物的高稳定性。
Studies on the Reactive Species in Fluoride-Mediated Carbon−Carbon Bond-Forming Reactions: Carbanion Formation by Desilylation with Fluoride and Enolates
作者:Margaret M. Biddle、Hans J. Reich
DOI:10.1021/jo0522409
日期:2006.5.1
bond-forming reactions was investigated. The regio- and diastereoselectivities of silanes reacting with cyclohexenone in the presence of a catalytic amount of fluoride was compared to the reactivity of analogous solvent-separated lithium ion pairs. Closely analogous behavior was observed, showing that carbanions and not siliconate complexes are the reactive species in the fluoride-catalyzed reactions. Spectroscopic
of sulfonium ylides generated from donor/acceptor diazoalkanes and propargyl sulfides. The reaction furnishes highly functionalized allenes from a broad range of starting materials in decent yield. Mechanistic experiments supported by the literature data suggest singlet carbenes as intermediates in this reaction.
Amination and [2,3]-sigmatropic rearrangement of propargylic sulfides using a ketomalonate-derived oxaziridine: synthesis of N-allenylsulfenimides
作者:Alan Armstrong、Richard S. Cooke、Stephen E. Shanahan
DOI:10.1039/b307722e
日期:——
Amination of propargylic sulfides with a ketomalonate-derived oxaziridine under metal free conditions gives N-Boc-N-allenylsulfenimides via [2,3]-sigmatropicrearrangement.