Quantitative Struktur-Wirkungs-Beziehung bei Polyhydroxyxanthonen, 2. Mitt.1): Synthese mehrfach oxigenierter 2-Hydroxyxanthone
摘要:
Es wird die Synthese der 2-Hydroxyxanthone 8 über die entsprechenden Polymethoxyxanthone 7 beschrieben, die in Ring C mehrfachhydroxyliert sind。Die Darstellung verläuft entweder über die 2-Phenoxybenzosäuren 5 or die polymethoxylierten 2-Hydroxybenzophenone 6。
Quantitative Struktur-Wirkungs-Beziehung bei Polyhydroxyxanthonen, 2. Mitt.1): Synthese mehrfach oxigenierter 2-Hydroxyxanthone
摘要:
Es wird die Synthese der 2-Hydroxyxanthone 8 über die entsprechenden Polymethoxyxanthone 7 beschrieben, die in Ring C mehrfachhydroxyliert sind。Die Darstellung verläuft entweder über die 2-Phenoxybenzosäuren 5 or die polymethoxylierten 2-Hydroxybenzophenone 6。
Palladium-Catalyzed Oxidative Double CH Functionalization/Carbonylation for the Synthesis of Xanthones
作者:Hua Zhang、Renyi Shi、Pei Gan、Chao Liu、Anxing Ding、Qiuyi Wang、Aiwen Lei
DOI:10.1002/anie.201201050
日期:2012.5.21
Two at once: Xanthones with different functional groups were obtained with CO (balloon) in the presence of a simple catalytic system that consists of Pd(OAc)2, K2S2O8, and trifluoroacetic acid (see scheme). Preliminary mechanism studies reveal that the second CHfunctionalization might be the rate‐determining step.
一次两个:在简单的催化体系(由Pd(OAc)2,K 2 S 2 O 8和三氟乙酸组成)的存在下,用CO(气球)获得具有不同官能团的氧杂蒽。初步的机理研究表明,第二个CH功能化可能是决定速率的步骤。
Friedel-Crafts-Type Alkylation with Bromodifluoro(phenylsulfanyl)methane through α-Fluorocarbocations: Syntheses of Thioesters, Benzophenones and Xanthones
Bromodifluoro(phenylsulfanyl)methane undergoes a Friedel–Crafts-typealkylation, throughα-fluorocarbocations, with activated aromatic compounds yielding thioesters and/or benzophenones. The methodology has been applied to the synthesis of naturally occurring xanthone derivatives.
Copper-catalyzed ortho-acylation of phenols with aryl aldehydes and its application in one-step preparation of xanthones
作者:Jun Hu、Enoch A. Adogla、Yong Ju、Daping Fan、Qian Wang
DOI:10.1039/c2cc36176k
日期:——
In the presence of triphenylphosphine, copper(II) chloride can catalyze an intermolecular ortho-acylation reaction of phenols with aryl aldehydes. The reaction proceeds smoothly with a wide range of starting materials, and furthermore, it can be used to synthesize xanthone derivatives in a single step in high yields.
One-Step Synthesis of Xanthones Catalyzed by a Highly Efficient Copper-Based Magnetically Recoverable Nanocatalyst
作者:Cintia A. Menéndez、Fabiana Nador、Gabriel Radivoy、Darío C. Gerbino
DOI:10.1021/ol500964e
日期:2014.6.6
A versatile and highlyefficient strategy to construct a xanthone skeleton via a ligand-free intermolecular catalytic coupling of 2-substituted benzaldehydes and a wide range of phenols has been developed. For this purpose, a novel and magneticallyrecoverable catalyst consisting of copper nanoparticles on nanosized silica coated maghemite is presented. The reaction proceeds smoothly with easy recovery
FeCl<sub>3</sub>and ether mediated direct intramolecular acylation of esters and their application in efficient preparation of xanthone and chromone derivatives
作者:Neng Jiang、Su-Yi Li、Sai-Sai Xie、Hequan Yao、Hongbin Sun、Xiao-Bing Wang、Ling-Yi Kong
DOI:10.1039/c4ra10174j
日期:——
The direct intramolecular acylation of esters was developed by using the combined system of FeCl3 with Cl2CHOCH3. This unique cooperative system offered a new and efficient approach to biologically important xanthone and chromone derivatives with regioselectivity. Examples were reported, and control experiments were carried out to examine the effect of the benzyl esters and Cl2CHOCH3.