Scope of the Palladium-Catalyzed Aryl Borylation Utilizing Bis-Boronic Acid
作者:Gary A. Molander、Sarah L. J. Trice、Steven M. Kennedy、Spencer D. Dreher、Matthew T. Tudge
DOI:10.1021/ja303181m
日期:2012.7.18
wasteful reagents to prepare boronic acid derivatives and require additional steps to afford the desired boronic acid. The scope of the previously reported palladium-catalyzed, direct boronic acid synthesis is unveiled, which includes a wide array of synthetically useful aryl electrophiles. It makes use of the newly available second generation Buchwald XPhos preformed palladium catalyst and bis-boronic
Abstract A facile new synthetic method for the preparation of a Type-A 1-arylnaphthalene lactone skeleton was developed and used to synthesise justicidin B and several derivatives. Key synthesis steps included Hauser–Kraus annulation of a phthalide intermediate and Suzuki–Miyaura cross coupling between a triflated naphthalene lactone intermediate and various potassium organotrifluoroborates. With two
摘要 开发了一种制备 A 型 1-芳基萘内酯骨架的简便新合成方法,并将其用于合成 justicidin B 和几种衍生物。关键的合成步骤包括苯酞中间体的 Hauser-Kraus 环化和三氟萘内酯中间体与各种有机三氟硼酸钾之间的 Suzuki-Miyaura 交叉偶联。除了两个例外,这些衍生物对脂多糖 (LPS) 诱导的小鼠巨噬细胞中一氧化氮 (NO) 的产生显示出显着的抑制作用。此外,包括 justicidin B 在内的几种化合物对六种人类肿瘤细胞系具有显着的细胞毒性。
Palladium-Catalyzed, Direct Boronic Acid Synthesis from Aryl Chlorides: A Simplified Route to Diverse Boronate Ester Derivatives
作者:Gary A. Molander、Sarah L. J. Trice、Spencer D. Dreher
DOI:10.1021/ja1089759
日期:2010.12.22
new boron reagents and identifying robust catalytic systems for the cross-coupling of these reagents, the fundamental preparations of the nucleophilic partners (i.e., boronicacids and derivatives) has been studied to a lesser extent. Most current methods to accessboronicacids are indirect and require harsh conditions or expensive reagents. A simple and efficient palladium-catalyzed, direct synthesis
A very short, high yielding, and convergent synthesis with broad substrate scope, enabling access to a very diverse range of hemithioindigos with 4-fold substituted double-bonds, is presented. With this method, carbon as well as nitrogen, oxygen, or sulfur based substituents can easily be introduced, delivering a wide array of novel structural motifs. Irradiation studies with visible light demonstrate proficient photoswitching properties of these chromophores at wavelengths up to 625 nm.
One-Pot Synthesis of Arylboronic Acids and Aryl Trifluoroborates by Ir-Catalyzed Borylation of Arenes
作者:Jaclyn M. Murphy、C. Christoph Tzschucke、John F. Hartwig
DOI:10.1021/ol062903o
日期:2007.3.1
The synthesis of arylboronic acids and aryl trifluoroborates in a one-pot sequence by Ir-catalyzed borylation of arenes is reported. To prepare the arylboronic acids, the Ir-catalyzed borylation is followed by oxidative cleavage of the boronic ester with NaIO4. To prepare the aryltrifluoroborate, the Ir-catalyzed borylation is followed by displacement of pinacol by KHF2. These two-step sequences give products that are more reactive toward subsequent chemistry than the initially formed pinacol boronates.