Lewis Acid Mediated [3+2] Coupling of Masked Benzoquinones with Styrenes: Facile Synthesis of 2,3-Dihydrobenzofurans
作者:Rama Peddinti、Shivangi Sharma、Santosh Parumala
DOI:10.1055/s-0036-1588622
日期:——
We have developed an efficient, simple, mild, and rapid method for the construction of dihydrobenzofuran derivatives by the [3+2] coupling of masked o-benzoquinones with styrene derivatives triggered by boron trifluoride diethyl etherate. This new [3+2] coupling protocol proceeds smoothly to afford dihydrobenzofuran derivatives in good to high yields within one minute. The method was extended to cycloaddition
Covalent Triazine Framework Nanoparticles via Size‐Controllable Confinement Synthesis for Enhanced Visible‐Light Photoredox Catalysis
作者:Wei Huang、Niklas Huber、Shuai Jiang、Katharina Landfester、Kai A. I. Zhang
DOI:10.1002/anie.202007358
日期:2020.10.12
copolymerizing small amounts of benzothiadiazole into the conjugated molecular network. This optimization of electronic properties led to a further increase in observed photocatalytic efficiency, resulting in total an 18‐fold enhancement compared to the bulk material. Full recyclability of the heterogeneousphotocatalysts as well as catalyticactivity in dehalogenation, hydroxylation and benzoimidazole formation
Photocatalytic Synthesis of Dihydrobenzofurans by Oxidative [3+2] Cycloaddition of Phenols
作者:Travis R. Blum、Ye Zhu、Sarah A. Nordeen、Tehshik P. Yoon
DOI:10.1002/anie.201406393
日期:2014.10.6
We report a protocol for oxidative [3+2] cycloadditions of phenols and alkenesapplicable to the modular synthesis of a large family of dihydrobenzofuran natural products. Visible‐light‐activated transition metal photocatalysis enables the use of ammonium persulfate as an easily handled, benign terminal oxidant. The broad range of organic substrates that are readily oxidized by photoredox catalysis
Iron-Catalyzed Oxidative Radical Cross-Coupling/Cyclization between Phenols and Olefins
作者:Zhiliang Huang、Liqun Jin、Ye Feng、Pan Peng、Hong Yi、Aiwen Lei
DOI:10.1002/anie.201210023
日期:2013.7.8
Selectively free: A highly efficient and selective iron‐catalyzedoxidative radical cross‐coupling/cyclization to prepare dihydrobenzofurans under mild conditions had been established. Phenols and olefins are directly utilized as clean nucleophiles. Mechanistic investigations revealed that the reaction proceeds through a radical pathway, and the high selectivity is due to the Lewis acid.
[3 + 2] Coupling of Quinone Monoacetals by Combined Acid–Hydrogen Bond Donor
作者:Toshifumi Dohi、Yinjun Hu、Tohru Kamitanaka、Naohiko Washimi、Yasuyuki Kita
DOI:10.1021/ol201886r
日期:2011.9.16
expeditious and efficient [3 + 2] coupling approach of quinonemonoacetals 1 with alkene nucleophiles 2 by the action of an activated Brønsted acid in the presence of a hydrogen bond donor perfluorinated alcohol has been achieved. With the optimized combined acid, the reaction could proceed under mild conditions by only mixing the two reactants to afford the cycloadducts 3 in a short time (within 10