One-pot synthesis of 2-methylfurans from 3-(trimethylsilyl)propargyl acetates promoted by trimethylsilyl trifluoromethanesulfonate
作者:Danielle E. Sklar、Alex V. Helbling、Yiqi Liu、C. Wade Downey
DOI:10.1016/j.tetlet.2021.153424
日期:2021.12
In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine, 3-(trimethylsilyl)propargyl carboxylates undergo a one-pot alkylation-cyclization-desilylation reaction with ketones to produce 2-methylfurans. Alkylation at 0 °C in methylene chloride, followed by acid-catalyzed cyclization at room temperature, provides the furans in 52–86% yield. Cyclization and desilylation appear
在三氟甲磺酸三甲基甲硅烷基酯 (TMSOTf) 和三乙胺的存在下,羧酸 3-(三甲基甲硅烷基)炔丙基酯与酮进行一锅烷基化-环化-脱甲硅烷基化反应,生成 2-甲基呋喃。在 0 °C 下在二氯甲烷中烷基化,然后在室温下酸催化环化,以 52-86% 的产率提供呋喃。环化和脱甲硅烷基化似乎由在初始取代反应完成后将反应混合物暴露于水中而原位生成的三氟甲磺酸促进。
Phosphine‐Catalyzed Activation of Alkylidenecyclopropanes: Rearrangement to Form Polysubstituted Furans and Dienones
作者:Xin He、Yuhai Tang、Yongzhuang Wang、Jian‐Bo Chen、Silong Xu、Jianwei Dou、Yang Li
DOI:10.1002/anie.201903320
日期:2019.7.29
We report a phosphine‐catalyzed ring opening of electron‐deficient alkylidenecyclopropanes (ACPs) to generate allylic phosphonium zwitterions that resemble the well‐studied phosphine‐allene adducts but exhibit distinct properties. The potent reactivity of these intermediates has been demonstrated in three types of substrate‐controlled phosphine‐catalyzed rearrangements of alkylidenecyclopropylketones
A regioselectivesynthesis of multisubstituted furan derivatives has been developed via Cu(II)-catalyzed intermolecular annulation of aryl ketones with a wide range of aromatic olefins under ambient air in good yields. This protocol is applicable to both cyclic and acyclic aryl ketones.
Synthesis of Tetrasubstituted Furans by Palladium-Catalyzed Decarboxylative [3+2] Cyclization of Propargyl β-Keto Esters
作者:Masahiro Yoshida、Shoko Ohno、Kozo Shishido
DOI:10.1002/chem.201103246
日期:2012.2.6
The decarboxylative [3+2] cyclization reaction of propargyl β‐ketoesters with a palladium catalyst is described. Tetrasubstituted furans with a variety of substituents were conveniently synthesized with high efficiency (see scheme).