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。
Oxidative alkylation/alkynylation of terminal alkenes <i>via</i> alkylaldehyde decarbonylation and 1,2-alkynyl migration
Alkenes and alkylaldehydes offer a general access to the challenging quaternary carbon-containing but-3-yn-1-ones through decarbonylation and 1,2-alkynyl migration.
3-<i>tert</i>
-Butyl-Substituted Cyclohexa-1,4-dienes as Isobutane Equivalents in the B(C<sub>6</sub>
F<sub>5</sub>
)<sub>3</sub>
-Catalyzed Transfer Hydro-<i>tert</i>
-Butylation of Alkenes
作者:Sebastian Keess、Martin Oestreich
DOI:10.1002/chem.201604397
日期:2017.5.2
equivalents when activated by the strong boron Lewis acid tris(pentafluorophenyl)borane. The hitherto unprecedented transfer hydro‐tert‐butylation from one unsaturated hydrocarbon to another is achieved with 1,1‐diarylalkenes as substrates, thereby presenting itself as a new way of incorporating tertiary alkyl groups into carbon frameworks. Transient carbocation intermediates give rise to competing reaction pathways
作者:Cornelia S. Buettner、Michael Schnürch、Katharina Bica-Schröder
DOI:10.1021/acs.joc.2c01304
日期:2022.8.19
aryl-alkenes affording C–C bonds using aryl-alkenes and alkyliodides. We demonstrate the formation of various hydroalkylation products in excellent yields, with primary, secondary, and tertiary alkyliodides being tolerated in the reaction. Mechanistic experiments reveal a pathway consisting of halogen atom transfer followed by a radical-polar crossover mechanism delivering the desired hydroalkylation products
Three-Component Cross-Electrophile 1,4-Alkylarylation of 1,3-Enynes by Merging Nickel and Photoredox Catalysis
作者:Quanyuan Wang、Ya Chen、Keyi Peng、Yue Li、Lilei Cheng、Guo-Jun Deng
DOI:10.1021/acs.orglett.3c03677
日期:2023.12.15
A three-component 1,4-alkylarylation of 1,3-enynes with organic halides through the combination of nickel and photoredox catalysis has been established, providing a novel and modular approach for the assembly of tetrasubstituted allenes. This reductive cascade cross-electrophile reaction obviates the need for air-sensitive organometallic reagents and stoichiometric metallic reductants. A diverse range