We report nickel-catalyzed cross-coupling of methoxyarenes with alkylmagnesium halides, in which a methoxy group is eliminated. A wide range of alkyl groups, including those bearing β-hydrogens, can be introduced directly at the ipso position of anisole derivatives. We demonstrate that the robustness of a methoxy group allows this alkylation protocol to be used to synthesize elaborate molecules by
我们报告了镍催化的甲氧基芳烃与烷基卤化镁的交叉偶联,其中甲氧基被消除。广泛的烷基,包括那些带有 β-氢的烷基,可以直接在苯甲醚衍生物的 ipso 位置引入。我们证明甲氧基的稳健性允许该烷基化方案通过将其与传统的交叉偶联反应或氧化转化相结合来合成复杂的分子。这种方法的成功取决于使用烷基碘化镁,而不是氯化物或溴化物,这突出了卤化物在使用格氏试剂进行催化反应中的重要性。
Cross-Coupling of Non-activated Chloroalkanes with Aryl Grignard Reagents in the Presence of Iron/<i>N</i>-Heterocyclic Carbene Catalysts
作者:Sujit K. Ghorai、Masayoshi Jin、Takuji Hatakeyama、Masaharu Nakamura
DOI:10.1021/ol2031729
日期:2012.2.17
An efficient and high-yielding cross-couplingreaction of various primary, secondary, and tertiary alkyl chlorides with aryl Grignard reagents was achieved by using catalytic amounts of N-heterocyclic carbene ligands and iron salts. This reaction is a simple and efficient arylation method having applicability to a wide range of industrially abundant chloroalkanes, including polychloroalkanes, which
Tantalum (or niobium)-alkyne complexes are produced by treatment of acetylenes with the low-valent tantalum (niobium) derived by zinc reduction of TaCl5 (NbCl5). Substituted 1-naphthols are prepared regioselectively by reaction of o-phthalaldehyde with the tantalum (or niobium)-alkyne complexes in good to excellent yields.
Visible-Light-Promoted Nickel-Catalyzed Cross-Coupling of Alkyltitanium Alkoxides with Aryl and Alkenyl Halides
作者:Andrei A. Leushukou、Anastasiya V. Krech、Alaksiej L. Hurski
DOI:10.1021/acs.orglett.2c02428
日期:2022.9.2
alkyltitanium alkoxides generated in situ from Grignardreagents and Ti(OiPr)4 undergo a photocatalyst-free nickel-catalyzedcross-coupling with organic halides upon irradiation with blue light. Mechanistic studies suggested that the reaction proceeds through radical intermediates formed by photochemical decomposition of the alkyltitanium reagents. Various aryl, heteroaryl, and vinyl halides were efficiently
在这里,我们报告了由格氏试剂和 Ti(O i Pr) 4原位生成的烷基钛醇盐在蓝光照射下与有机卤化物发生无光催化剂镍催化的交叉偶联。机理研究表明,反应通过烷基钛试剂的光化学分解形成的自由基中间体进行。各种芳基、杂芳基和乙烯基卤化物在报告的条件下被有效地烷基化,包括那些含有酯和酰胺基团的。
Koelbel et al., Brennstoff-Chemie, 1959, vol. 40, p. 281,282-285