General method for iron-catalyzed multicomponent radical cascades–cross-couplings
作者:Lei Liu、Maria Camila Aguilera、Wes Lee、Cassandra R. Youshaw、Michael L. Neidig、Osvaldo Gutierrez
DOI:10.1126/science.abj6005
日期:2021.10.22
addition to vinyl boronates) with Grignard reagents. Then, we extended the scope of these radical cascades by developing a general and broadly applicable Fe-catalyzed multicomponent annulation–cross-coupling protocol that engages a wide range of π-systems and permits the practical synthesis of cyclic fluorous compounds. Mechanistic studies are consistent with a bisarylated Fe(II) species being responsible
过渡金属催化的交叉偶联反应是化学合成中应用最广泛的一些方法。然而,尽管铁 (Fe) 作为一种潜在的更便宜、更丰富、毒性更小的过渡金属催化剂具有显着优势,但其在多组分交叉偶联中的实际应用仍然很大程度上不成功。我们展示了 1,2-双(二环己基膦基)乙烷 Fe 催化的 α-硼基自由基(由选择性自由基加成到乙烯基硼酸盐产生)与格氏试剂的偶联。然后,我们通过开发一种通用且广泛适用的 Fe 催化多组分环化-交叉偶联方案扩展了这些自由基级联的范围,该方案涉及广泛的 π 系统并允许实际合成环状氟化合物。
Fe-catalyzed three-component dicarbofunctionalization of unactivated alkenes with alkyl halides and Grignard reagents
作者:Lei Liu、Wes Lee、Cassandra R. Youshaw、Mingbin Yuan、Michael B. Geherty、Peter Y. Zavalij、Osvaldo Gutierrez
DOI:10.1039/d0sc02127j
日期:——
reported. The reaction operates under fast turnover frequency and tolerates a diverse range of sp2-hybridized nucleophiles (electron-rich and electron-deficient (hetero)aryl and alkenyl Grignard reagents), alkyl halides (tertiary alkyl iodides/bromides and perfluorinated bromides), and unactivated olefins bearing diversefunctional groups including tethered alkenes, ethers, protected alcohols, aldehydes
Fe-Catalyzed dicarbofunctionalization of electron-rich alkenes with Grignard reagents and (fluoro)alkyl halides
作者:Madeline E. Rotella、Dinabandhu Sar、Lei Liu、Osvaldo Gutierrez
DOI:10.1039/d1cc04619e
日期:——
electron-rich alkenes is described. In particular, aryl- and alkyl vinyl ethers are used as effective linchpins to couple alkyl or (fluoro)alkyl halides and sp2-hybridized Grignard nucleophiles. Preliminary results demonstrate the ability to engage thioethers as linchpins and control enantioselectivity in these transformations, an area which is largely unexplored in iron-catalyzed three-component cross-coupling
Intra- and intermolecular Fe-catalyzed dicarbofunctionalization of vinyl cyclopropanes
作者:Lei Liu、Wes Lee、Mingbin Yuan、Chris Acha、Michael B. Geherty、Brandon Williams、Osvaldo Gutierrez
DOI:10.1039/d0sc00467g
日期:——
halides and arylGrignardreagents has been realized via a mechanistically driven approach. Mechanistic studies support the diffusion of alkyl radical intermediates out of the solvent cage to participate in an intra- or intermolecular radical cascade with a range of VCPs followed by re-entering the Fe radical cross-coupling cycle to undergo (stereo)selective C(sp2)–C(sp3) bondformation. This work provides
Organophotoredox-Catalyzed Reductive Tetrafluoroalkylation of Alkenes
作者:Vladislav S. Kostromitin、Vitalij V. Levin、Alexander D. Dilman
DOI:10.1021/acs.joc.2c00712
日期:——
A method for the hydroperfluoroalkylation of alkenes with 1,2-dibromotetrafluoroethane leading to tetrafluorinated bromides is described. The reaction is conveniently performed under blue light irradiation using an organic photocatalyst and ascorbic acid as a reducing agent. Primary products can be further functionalized via radical pathways affording various tetrafluorinated compounds.