Iron-Catalyzed C-Allylating Partial Dearomatization of Naphthols
摘要:
The iron complex Bu4N[Fe(CO)(3)(NO)](TBA[Fe]) catalyzes the intermolecular allylation of naphthol derivatives to give the corresponding partially dearomatized allylated chromenones in good to excellent yields. The scope and limitations are reported. An efficient decarboxylative intramolecular C- allylation, starting from allyl naphthyl carbonates, was developed. From a mechanistic point of view, the overall process is the result of a fast O- allylation followed by a sigmatropic rearrangement to the desired product.
Iron-Catalyzed C-Allylating Partial Dearomatization of Naphthols
摘要:
The iron complex Bu4N[Fe(CO)(3)(NO)](TBA[Fe]) catalyzes the intermolecular allylation of naphthol derivatives to give the corresponding partially dearomatized allylated chromenones in good to excellent yields. The scope and limitations are reported. An efficient decarboxylative intramolecular C- allylation, starting from allyl naphthyl carbonates, was developed. From a mechanistic point of view, the overall process is the result of a fast O- allylation followed by a sigmatropic rearrangement to the desired product.
Intermediacy of Ni–Ni Species in sp<sup>2</sup> C–O Bond Cleavage of Aryl Esters: Relevance in Catalytic C–Si Bond Formation
作者:Rosie J. Somerville、Lillian V. A. Hale、Enrique Gómez-Bengoa、Jordi Burés、Ruben Martin
DOI:10.1021/jacs.8b04479
日期:2018.7.18
esters with monodentate phosphines and low-valent nickel complexes still remains elusive. Herein, we report a combined experimental and theoretical study on the Ni(0)/PCy3-catalyzed silylation of aryl pivalates with CuF2/CsF additives that reveals the involvement of unorthodox dinickel oxidative addition complexes in C-O bond cleavage and their relevance in C-Si bond formation. We have obtained a mechanistic
单齿膦配体经常用于芳基酯的镍催化 CO 官能化。然而,关于此类反应的大量准备工作与缺乏有关相关镍中间体的结构和反应性的信息形成鲜明对比。事实上,对于芳酯与单齿膦和低价镍配合物的 CO 键的看似微不足道的氧化加成的实验证据仍然难以捉摸。在此,我们报告了 Ni(0)/PCy3 催化的新戊酸芳基与 CuF2/CsF 添加剂的硅烷化的联合实验和理论研究,揭示了非正统二镍氧化加成配合物参与 CO 键断裂及其与 C-Si 的相关性键的形成。我们获得了一张机械图,阐明了添加剂的作用,并证明了二镍配合物通过歧化作用作为传播的单体镍配合物的储库。我们相信这项研究将作为一个有用的切入点,以解开使用单齿膦的其他相关镍催化 CO 功能化反应的机制基础。
Insights into the Enantioselective Au(I)‐Catalyzed Reactions between 2‐Alkynyl Ketones and Naphthols using the TCDC Approach
chiral Au(I) catalyst (S)-3 a, but mainly from a chirality transfer from the substrate (Scheme 3, eq. 8). The transfer of chirality from 4 a to 5 a, which can be estimated from the extrapolated initial er value of 5 a, is higher when using (S)-4 a (about 86%) than using (R)-4 a (about 76%). This demonstrates a certain degree of match effect between (S)-4 a and the (S)-configured catalyst and mismatch
Iron-Catalyzed Dioxygen-Driven C–C Bond Formation: Oxidative Dearomatization of 2-Naphthols with Construction of a Chiral Quaternary Stereocenter
作者:Takuya Oguma、Tsutomu Katsuki
DOI:10.1021/ja310203c
日期:2012.12.12
Iron(salan) complex 1 was found to catalyze the oxidative dearomatization of 1-substituted 2-naphthols with the formation of an all-carbon quaternary stereocenter in air in the presence of nitroalkanes, to afford the corresponding cyclic enones with high enantioselectivity of 88-96% ee.