Radical Dehydroxylative Alkylation of Tertiary Alcohols by Ti Catalysis
作者:Hao Xie、Jiandong Guo、Yu-Quan Wang、Ke Wang、Peng Guo、Pei-Feng Su、Xiaotai Wang、Xing-Zhong Shu
DOI:10.1021/jacs.0c07492
日期:2020.9.30
coupling partners, including allylic carboxylates, aryl and vinyl electrophiles, and primary alkyl chlorides/bromides, making the method complementary to the cross-coupling procedures. The method is highlyselective for the alkylation of tertiary alcohols, leaving secondary/primary alcohols (benzyl alcohols included) and phenols intact. The synthetic utility of the method is highlighted by its 10-gram-scale
醇的脱氧自由基 CC 键形成反应是合成化学中长期存在的挑战,目前的方法依赖于多步骤程序。在此,我们报告了叔醇的直接脱羟基自由基烷基化反应。这一新协议显示了从醇类中生成叔碳自由基的可行性,并为轻松精确地构建全碳四元中心提供了一种方法。该反应在醇和活化烯烃的广泛底物范围内进行。它可以耐受各种亲电偶联伙伴,包括烯丙基羧酸盐、芳基和乙烯基亲电试剂以及伯烷基氯/溴化物,使该方法与交叉偶联程序形成互补。该方法对叔醇的烷基化具有高度选择性,保持仲醇/伯醇(包括苯甲醇)和酚类完好无损。该方法的合成效用因其 10 克规模的反应和复杂分子的后期修饰而突出。实验和 DFT 计算的组合建立了一个合理的机制,暗示通过 Ti 催化的 C-OH 键均裂产生叔碳自由基。
Catalytic B(C6F5)3H2O-promoted defluorinative functionalization of tertiary aliphatic fluorides
A B(C6F5)3H2O-catalyzed defluorinative functionalization of tertiary aliphaticfluorides is described that proceeds under benign reaction conditions. The synthetic utility of the method is exemplified through the fast and efficient formation of a range of products with newly installed C(sp3) N, S, C and O bonds. This study illustrates the broad reactivity of otherwise inert starting materials and provides
描述了在良性反应条件下进行的AB(C 6 F 5)3 H 2 O催化的叔脂肪族氟化物的脱氟官能化。通过快速有效地形成一系列具有新安装的C(sp 3)N,S,C和O键的产品,可以举例说明该方法的综合用途。这项研究说明了其他惰性原料的广泛反应性,并提供了通往有价值的和合成上代表性不足的产品的途径,这些产品以前从未从此类氟化前体中获得。
InCl<sub>3</sub>/I<sub>2</sub>-Catalyzed Cross-Coupling of Alkyl Trimethylsilyl Ethers and Allylsilanes via an in Situ Derived Combined Lewis Acid of InCl<sub>3</sub> and Me<sub>3</sub>SiI
作者:Takahiro Saito、Yoshihiro Nishimoto、Makoto Yasuda、Akio Baba
DOI:10.1021/jo7015289
日期:2007.10.1
Direct Csp3−Csp3 coupling of various aliphatic trimethylsilyl ethers and allylsilanes is effectively catalyzed by InCl3 and I2. The transformation is thought to involve an in situ-derived combined Lewis acid of InCl3 and Me3SiI. The reaction can be used for the construction of quaternary−quaternary and quaternary−tertiary carbon−carbon bonds. This system enabled a highly chemoselective coupling to
InCl 3和I 2有效地催化了各种脂族三甲基甲硅烷基醚和烯丙基硅烷的直接C sp3- C sp3偶联。认为该转化涉及InCl 3和Me 3 SiI的原位结合的路易斯酸。该反应可用于构建季-季和季-季碳-碳键。该系统使得能够与包括芳基卤化物部分的三甲基甲硅烷基醚进行高度化学选择性的偶联。此外,可以使用炔基三甲基硅烷和三甲基甲硅烷基乙烯酮缩醛进行偶联。
The Migration Aptitude of Substituted Benzyl vs. Methyl in Carbonium Ion Reactions of the 2,2-Dimethyl-3-aryl-1-propyl System. The Question of Alkyl Participation<sup>1</sup>
作者:John R. Owne、William H. Saunders
DOI:10.1021/ja00976a022
日期:1966.12
Selective Liquid-Phase Semihydrogenation of Functionalized Acetylenes and Propargylic Alcohols with Silica-Supported Bimetallic Palladium−Copper Catalysts
作者:Marieke P. R. Spee、Jaap Boersma、Michel D. Meijer、Martijn Q. Slagt、Gerard van Koten、John W. Geus
DOI:10.1021/jo001246p
日期:2001.3.1
Silica-supported, bimetallic palladium-copper catalysts were prepared in solution under mild conditions by reacting lithium di(4-tolyl)cuprate with palladium acetate in the presence of silica particles. Small bimetallic palladium-copper particles were deposited on the silica surface as confirmed with TEM-EDAX and EXAFS. The new material has been applied as catalyst in the liquid-phase semihydrogenation of mono- and disubstituted alkynes and showed high selectivity toward the cis-alkenes. The influence of addition of quinoline or potassium hydroxide to the semihydrogenation reaction mixture and the effects of exposure of the catalyst to air before use have been investigated.