The palladium(II) acetate catalyzed reaction of phenyliodonium ylides of 2-hydroxyquinones with arylboronicacids affords a variety of 3-substituted 2-hydroxyquinone derivatives. Best yields are obtained by using tri(tert-butyl)phosphine as a ligand.
乙酸钯 (II) 催化 2-羟基醌的苯基碘鎓叶立德与芳基硼酸反应得到多种 3-取代的 2-羟基醌衍生物。使用三(叔丁基)膦作为配体可获得最佳产率。
Sc(OTf)3‐Catalyzed Synthesis of 3‐Substituted Lawsones through a Buchner‐Curtius‐Schlotterbeck Reaction
作者:Sailam Sri Gogula、Dasari Vijaya Prasanna、B. Sridhar、Ch. Abraham Lincoln、P. Muralidhar Reddy、B. V. Subba Reddy
DOI:10.1002/ejoc.202400362
日期:2024.8.19
An efficient method has been developed for the synthesis of 3-substituted lawsones using 10 mol % Sc(OTf)3 in toluene at −78 °C through a Buchner-Curtius-Schlotterbeck reaction. This method is simple and convenient to the synthesis of pharmaceutically relevant 3-substituted lawsones in high to excellent yields.
开发了一种有效的方法,使用 10 mol% Sc(OTf) 3在甲苯中,在 -78 °C 下通过布赫纳-库尔蒂斯-施洛特贝克反应合成 3-取代的指甲花酮。该方法简单方便,可以高收率合成药学相关的3-取代指甲花酮。
Styryl and functionalized aryl derivatives of lawsone through metal-free cross-coupling of its BF3-activated phenyliodonium ylide with cinnamaldehydes and arylaldehydes
Phenyliodonium ylide of lawsone activated with BF3 center dot Et2O reacts with cinnamaldehydes to afford 2-hydroxy-3-styryl-1,4-naphthoquinones in good to excellent yields and relatively high level of stereospecificity through deformylation of the aldehydes. The product yield is diminished with a methoxy substituted cinnamaldehyde and becomes zero with a dimethoxy substituted substrate giving rise to another product, 2-hydroxy-3-aryl-1,4-naphthoquinone. The reaction of the same ylide with salicylic aldehydes forms 2-hydroxy-3-(2-hydroxyary1)-1,4-naphthoquinones and/or benzo[d]naphtha[2,1-b]furano-5,6-diones, depending on the reaction conditions applied. Plausible reaction mechanisms explaining the formation of these products are proposed. The products showed potent antioxidant activity and inhibited lipoxygenase. (C) 2015 Elsevier Ltd. All rights reserved.