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
Nucleophilic Solvent Participation in the Solvolysis of Tertiary Bromoalkanes
作者:Kwang-Ting Liu、Su-Jiun Hou、Meng-Lin Tsao
DOI:10.1002/jccs.200900063
日期:2009.4
indicated limiting SN1 mechanism for the solvolysis. On the other hand, bromides 1B‐6B and 8B gave linear correlations (R = 0.987–0.996) with the dual‐parameter (YBr and NOTs) equation (2) only, which indicated the presence of significant nucleophilic solvent participation. Normal trends of reactivity due to the relief of B‐strain could be found in the poorly nucleophilic trifluoroethanol. Similar to the corresponding
A comparative study of the heterolysis reactions of 3-X-3-methylpentanes (X = Cl, Br, I) in a set of protic and aproticsolvents was performed at 25.00°C. Rate constant values were correlated with solvent descriptors using the TAKA multiparametric equation. Our results point towards a decrease in both hydrogen bond donor acidity (electrophilicity) and hydrogen bond acceptor basicity (nucleophilicity)
We report a novel Ru-catalyzed regioselective alkylarylation of vinylarenes with alkylhalides and arenes via meta-C(sp2)–H bond functionalization to construct 1,1-diarylalkanes that generally show bioactivity. In this transformation, a wide spectrum of primary, secondary, and tertiary alkylhalides and electronically varied arenes was well-tolerated. This reaction is characterized by its exquisite