Mesoporous aluminosilicate-catalyzed allylation of carbonyl compounds and acetals
摘要:
A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both carbonyl compounds and acetals with allylsilanes to afford the corresponding homoallyl silyl ethers and homoallyl alkyl ethers, respectively. Both the mesoporous structure and the presence of aluminum moiety were indispensable for the high catalytic activity of Al-MCM-41. Moreover, Al-MCM-41 could catalyze the reaction of acetals chemoselectively in the presence of the corresponding carbonyl compounds. The solid acid catalyst Al-MCM-41 could be recovered easily by filtration and could be reused three times without a significant loss of catalytic activity. (C) 2011 Elsevier Ltd. All rights reserved.
Traceless OH-Directed Wacker Oxidation-Elimination, an Alternative to Wittig Olefination/Aldol Condensation: One-Pot Synthesis of <i>α</i>,<i>β</i>-Unsaturated and Nonconjugated Ketones from Homoallyl Alcohols
作者:Venkati Bethi、Rodney A. Fernandes
DOI:10.1021/acs.joc.6b01899
日期:2016.9.16
A new method for one-pot synthesis of β-substituted and β,β-disubstituted α,β-unsaturated methyl ketones from homoallyl alcohols by sequential PdCl2/CrO3-promoted Wacker process followed by an acid-mediated dehydration reaction has been developed. Remarkably, internal homoallyl alcohols delivered regioselectively nonconjugated unsaturated carbonyl compounds under the same protocol. A new starting material-based
Rapid and Solvent-Free Synthesis of Homoallyl or Homopropargyl Alcohols Mediated by Zinc Powder
作者:Jin-xian Wang、Xuefeng Jia、Tuanjie Meng、Li Xin
DOI:10.1055/s-2005-872178
日期:——
A rapid and efficient procedure for the solvent-free synthesis of homoallylic and homopropargyl alcohols has been achieved by zinc-mediated Barbier-type reaction of carbonyl compounds at room temperature.
of α‐methylene‐γ‐lactones through the palladium(II)‐catalyzed lactonization of homoallylic alcohols with alkynamides has been reported. The hydroxyl group in the terminal olefins cooperates with the amide in alkynamides to promote the cyclization by suppressing the β‐H elimination. This process provides a route to construct naturally occurring biologically multifunctional α‐methylene‐γ‐lactones.
mild catalytic allylation of carbonyl compounds, applicable to aldehydes, ketones, and imines is developed using allyltrimethoxysilane as the allylating reagent. The reaction proceeds smoothly with 1-10 mol % of CuCl and TBAT in THF at ambient temperature. Mechanism studies indicated that the copper alkoxide, allylfluorodimethoxysilane, and allyltrimethoxysilane are essential to promote the reaction
Catalytic Use of Indium(0) for Carbon−Carbon Bond Transformations in Water: General Catalytic Allylations of Ketones with Allylboronates
作者:Uwe Schneider、Masaharu Ueno、Shu̅ Kobayashi
DOI:10.1021/ja804182j
日期:2008.10.22
We have discovered the unprecedented catalytic use of In(0) for catalytic C-C bond transformations. Remarkably, these generalcatalytic allylations of ketones proceeded smoothly in water as a sole solvent under mild conditions, and water proved to be essential for these reactions. Both the displayed substrate scope and the functional group tolerance were excellent. Importantly, the In metal catalyst
我们发现了 In(0) 在催化 CC 键转换中前所未有的催化用途。值得注意的是,这些酮的一般催化烯丙基化反应在温和条件下在作为唯一溶剂的水中顺利进行,并且水被证明是这些反应必不可少的。显示的底物范围和官能团耐受性都非常好。重要的是,In 金属催化剂可以很容易地回收和重复使用,而不会损失催化活性。此外,当使用 α 取代的烯丙基硼酸酯时,观察到不寻常的结构选择性,仅提供正式的 α 加合物。此外,得到的叔均烯丙基醇具有极高的非对映选择性。