Regioselective Single-Electron Tsuji–Trost Reaction of Allylic Alcohols: A Photoredox/Nickel Dual Catalytic Approach
作者:Zheng-Jun Wang、Shuai Zheng、Eugénie Romero、Jennifer K. Matsui、Gary A. Molander
DOI:10.1021/acs.orglett.9b02473
日期:2019.8.16
A radical-mediated functionalization of allyl alcohol derived partners with a variety of alkyl 1,4-dihydropyridines via photoredox/nickel dual catalysis is described. This transformation transpires with high linear and E-selectivity, avoiding the requirement of harsh conditions (e.g., strong base, elevated temperature). Additionally, using aryl sulfinate salts as radical precursors, allyl sulfones
Iron-catalysed allylation–hydrogenation sequences as masked alkyl–alkyl cross-couplings
作者:Josef Bernauer、Guojiao Wu、Axel Jacobi von Wangelin
DOI:10.1039/c9ra07604b
日期:——
organomagnesium reagents (alkyl, aryl) with simple allyl acetates proceeds under mild conditions (Fe(OAc)2 or Fe(acac)2, Et2O, r.t.) to furnish various alkene and styrene derivatives. Mechanistic studies indicate the operation of a homotopic catalyst. The sequential combination of such iron-catalysed allylation with an iron-catalysed hydrogenation results in overall C(sp3)–C(sp3)-bond formation that constitutes
在温和条件下(Fe(OAc) 2或 Fe(acac) 2 , Et 2 O, rt),有机镁试剂(烷基、芳基)与简单的乙酸烯丙酯发生铁催化烯丙基化反应,得到各种烯烃和苯乙烯衍生物。机理研究表明了同伦催化剂的运作。这种铁催化烯丙基化与铁催化氢化的顺序组合导致整体C(sp 3 )–C(sp 3 )-键形成,这构成了具有挑战性的与烷基卤化物的直接交叉偶联方案的有吸引力的替代方案。
Visible light-driven conjunctive olefination
作者:Dario Filippini、Mattia Silvi
DOI:10.1038/s41557-021-00807-x
日期:2022.1
Here we report a visible-light-mediated and transition metal-free conjunctive olefination that uses an alkene ‘linchpin’ with a defined geometry to cross-couple complex molecular scaffolds that contain carboxylic acids and aldehydes. The chemistry merges two cornerstones of organic synthesis—namely, the Wittig reaction and photoredox catalysis—in a catalytic cycle that couples a radical addition process
Nickel-Catalyzed Cross-Coupling of Alkyl Zinc Halides for the Formation of C(sp<sup>2</sup>)C(sp<sup>3</sup>) Bonds: Scope and Mechanism
作者:Vilasâ B. Phapale、Manuel Guisán-Ceinos、Elena Buñuel、Diegoâ J. Cárdenas
DOI:10.1002/chem.200901913
日期:2009.11.23
Optimal conditions for a general Ni‐catalysed Negishi cross‐coupling of alkyl zinc halides with aryl, heteroaryl and alkenyl halides have been determined. These conditions allow the reaction to take place smoothly, with low catalyst loading, and in the presence of a wide variety of functional groups to afford products in good yields at room temperature. DFT studies on the mechanism support the occurrence
Iridium-Catalyzed, Diastereoselective Dehydrogenative Silylation of Terminal Alkenes with (TMSO)<sub>2</sub>MeSiH
作者:Chen Cheng、Eric M. Simmons、John F. Hartwig
DOI:10.1002/anie.201304084
日期:2013.8.19
achieved under mild conditions with low catalyst loading. The diastereoselectivity of the reaction can be controlled by choosing the appropriate ancillary ligand (see scheme; coe=cyclooctene). The silylation products undergo further transformation such as oxidation or cross‐coupling.