通过1-萘酚的电子供体-受体配合物的氧化反应,通过氧化反应,直接合成2,2'-联萘醌和二萘并[1,2- b ; 2',1'- d ]呋喃的简单方法。在不存在或存在双氧的情况下的SnCl 4。作为该方法在天然产物合成中的应用,我们描述了几种双萘甲醌,3,3'-双juglone,3,3'-biplumbagin和艾力汀的简便仿生合成方法。
developed a simple method for the direct synthesis of 2,2′-binaphthoquinones, utilizing oxidative dimerization via electron donor–acceptor complex formation of 1-naphthols with SnCl4 in the presence of dioxygen. This oxidation involves a catalytic cycle of SnCl4, and the reaction mechanism is discussed. As an application of this method to natural products synthesis, we describe facile biomimetic syntheses
A simple method was developed for the direct synthesis of 2,2′-binaphthoquinones and dinaphtho[1,2-b;2′,1′-d]furans, utilizing an oxidative reaction via electron donor–acceptor complexes of 1-naphthols with SnCl4 in the absence or presence of dioxygen. As an application of this method to natural product synthesis, we describe a facile biomimetic synthesis of several binaphthoquinones, 3,3′-bijuglone
通过1-萘酚的电子供体-受体配合物的氧化反应,通过氧化反应,直接合成2,2'-联萘醌和二萘并[1,2- b ; 2',1'- d ]呋喃的简单方法。在不存在或存在双氧的情况下的SnCl 4。作为该方法在天然产物合成中的应用,我们描述了几种双萘甲醌,3,3'-双juglone,3,3'-biplumbagin和艾力汀的简便仿生合成方法。
SnCl 4 -mediated oxidative biaryl coupling reaction of 1-naphthol and subsequent ring closure of 2,2′-binaphthol to the dinaphthofuran framework
A simple method for the direct synthesis of 2,2′-binaphthols 2 and dinaphtho[1,2-b;2′,1′-d]furans 3 under mild conditions was developed, utilizing a biaryl coupling reaction via electron donor–acceptor complexes of 1-naphthols with SnCl4. Heating of the complex in a sealed tube for (18–24 h) afforded the corresponding o–o coupled product 2 in excellent yield. Prolonged reaction (56–65 h) under the
利用电子供体-受体的联芳基偶联反应,开发了一种在温和条件下直接合成2,2'-联萘酚2和二萘并[1,2- b ; 2',1'- d ]呋喃3的简单方法1-萘酚与SnCl 4的配合物。该复合物在密封管中加热(18-24小时),得到相应的ö - ö偶联产物2的优良率。在相同条件下长时间反应(56–65小时)一步即可获得3的高收率。我们还发现,对于在C-1位上没有羟基以外的取代基的α-萘酚,区域选择性o –o进行了偶联反应。产物2a,2b和2g应该用作天然存在的3,3′-双juglone,3,3′-biplumbagin和艾力汀的合成中间体。
Reactions of 1-Naphthols with .PI.-Acceptor p-Benzoquinones: Oxidative Aryl Coupling vs. Non-Oxidative Electrophilic Arylation
We investigated the reactions of various 1-naphthols (NPOHs; 1) with p-benzoquinones (Qs), such as 1,4-benzoquinone (BQ) and p-chloranil (CA), as π-electron acceptors. With electron-rich NPOHs 1a—c, oxidative biaryl coupling and subsequent dehydrogenation reaction took place selectively to give the corresponding 2,2′-binapthyl-1,1′-quinones 3a—c in excellent yield. In the case of electron-deficient NPOHs 1e, f, two different types of reactions occurred in the presence of SnCl4 and ZrO2 under similar conditions: SnCl4 mediated oxidative dimerization and trimerization of NPOH, while ZrO2 promoted electrophilic arylation of Qs with NPOH. The resulting products 3 would be useful synthetic intermediates for naturally occurring diosindigo B, biramentaceone and violet-quinone.