Reduction of a series of substituted flavanones afforded synthetic access to flavan-4-ols and was followed for some of them by an SN2-type acid-catalysis in methanol to provide 4-methoxyflavans. The stereochemistry of these compounds was established by 1H and 13C NMR data. Flavan-4-ols and 4-methoxyflavans have been resolved into enantiomers which are being evaluated as anticancer drugs.
一系列得到合成获得黄烷-4-醇和取代的黄烷酮的还原,随后进行由S它们中的一些Ñ在甲醇2类型的酸催化,以提供4- methoxyflavans。这些化合物的立体化学由1 H和13 C NMR数据确定。黄烷-4-醇和4-甲氧基黄烷已被解析为对映体,其被评估为抗癌药。
Palladium-catalyzed coupling of N-tosylhydrazones and β-bromostyrene derivatives: new approach to 2H-chromenes
作者:Yamu Xia、Ying Xia、Yan Zhang、Jianbo Wang
DOI:10.1039/c4ob01979b
日期:——
structural motif that exists in natural products and non-natural compounds possessing interesting biological activities. In this investigation, a highly efficient approach toward 2H-chromenes has been developed based on palladium-catalyzedcoupling of N-tosylhydrazones and β-bromostyrenes. The mechanism of this reaction is proposed that involves the formation of vinyl palladium by carbene migratory insertion
2 H -Chromene是存在于天然产物和具有有趣生物活性的非天然化合物中的重要结构基序。在这项研究中,基于钯催化的N-甲苯磺酰hydr和β-溴苯乙烯的偶联,已经开发出一种高效的2 H-苯甲基苯胺的方法。提出了该反应的机理,该机理涉及通过卡宾迁移插入和分子内亲核取代形成乙烯基钯。
Synthesis of 2-Acylphenol and Flavene Derivatives from the Ruthenium-Catalyzed Oxidative C-H Acylation of Phenols with Aldehydes
作者:Hanbin Lee、Chae S. Yi
DOI:10.1002/ejoc.201403518
日期:2015.3
[(C6H6)(PCy3)(CO)RuH]+BF4- has been found to be an effective catalyst for the oxidativeC-H coupling reaction of phenols with aldehydes to give 2-acylphenol compounds. The coupling of phenols with α,β-unsaturated aldehydes selectively gives the flavenederivatives. The catalytic method mediates direct oxidativeC-H coupling of phenol and aldehyde substrates without using any metal oxidants or forming wasteful byproducts
Nickel-Catalyzed Cross-Coupling of Chromene Acetals and Boronic Acids
作者:Thomas J. A. Graham、Abigail G. Doyle
DOI:10.1021/ol300364s
日期:2012.3.16
nes is described. Under base-free conditions, readily accessible 2-ethoxy-2H-chromenes undergo Csp3–O activation and Csp3–C bond formation in the presence of an inexpensive nickel catalyst and boronicacids. This new strategy enables broad access to 2-substituted-2H-chromenes and has been applied to the late-stage incorporation of complex molecules, including the pharmaceuticals loratidine and indomethacin
描述了一种用于合成 2-芳基-和杂芳基-2 H-色烯的模块化和高效方案。在无碱条件下,容易获得的 2-乙氧基-2 H-色烯在廉价的镍催化剂和硼酸存在下经历 C sp 3 -O 活化和 C sp 3 -C 键形成。这种新策略可以广泛使用 2-取代-2 H-色烯,并已应用于复杂分子的后期掺入,包括药物氯雷他定和吲哚美辛甲酯。
The Reactions of 2-Phenyl-2<i>H</i>-1-benzopyrans and 2-Phenyl-4<i>H</i>-1-benzopyrans with Lead(IV) Acetate
7-methoxy-2-phenyl-2H-1-benzopyran and 7-methoxy-2-phenyl-4H-1-benzopyran with lead(IV) acetate gave 2-benzoyl-6-methoxybenzofuran and 6-acetoxy-3-methoxy-6-(3-oxo-3-phenyl-1 -propenyl)-2,4-cyclo-hexadien-1-one. The reactions of 7-methoxy-2-(p-methoxy-phenyl)-2H-1-benzopyran and 7-methoxy-2-(p-methoxyphen-yl)-4H-1-benzopyran with lead(IV) acetate also gave the corresponding benzofuran and cyclohexadienone. The reaction