Selective C-H Fluorination of Pyridines and Diazines Inspired by a Classic Amination Reaction
作者:Patrick S. Fier、John F. Hartwig
DOI:10.1126/science.1243759
日期:2013.11.22
Fluorinating Pyridine Appending fluorine substituents to carbon centers is commonly used to tune small-molecule properties in pharmaceutical and agrochemical research. However, fluorinations often require the use of corrosive, hazardous reagents. Fier and Hartwig (p. 956) present an unusually mild and convenient protocol for fluorinating carbon sites adjacent to nitrogen in pyridines and related nitrogen-bearing
Combined Iron/Hydroxytriazole Dual Catalytic System for Site Selective Oxidation Adjacent to Azaheterocycles
作者:Julian C. Cooper、Chaosheng Luo、Ryohei Kameyama、Jeffrey F. Van Humbeck
DOI:10.1021/jacs.7b12864
日期:2018.1.31
This report details a new method for site-selective methylene oxidation adjacent to azaheterocycles. A dual catalysis approach, utilizing both an iron Lewis acid and an organic hydroxylamine catalyst, proved highly effective. We demonstrate that this method provides complementary selectivity to other known catalytic approaches and represents an improvement over current heterocycle-selective reactions
cannot be used for skeletal editing of pyridines. Here we report the direct skeletal editing of pyridines through atom-pair swap from CN to CC to generate benzenes and naphthalenes in a modular fashion. Specifically, we use sequential dearomatization, cycloaddition and rearomatizing retrocycloaddition reactions in a one-pot sequence to transform the parent pyridines into benzenes and naphthalenes bearing
骨架编辑是一种简单的合成策略,用于精确替换或重排复杂分子核心环结构中的原子;它可以实现化合物的快速多样化,这是通过应用外围编辑策略不可能实现的。先前报道的常见芳烃的骨架编辑主要依赖于卡宾或氮宾类型的插入反应或重排。尽管这些策略功能强大、高效且适用于后期杂芳烃核心结构修饰,但不能用于吡啶的骨架编辑。在这里,我们报告了通过从 CN 到 CC 的原子对交换对吡啶进行直接骨架编辑,以模块化方式生成苯和萘。具体来说,我们在一锅序列中使用顺序脱芳构化、环加成和再芳构化逆环加成反应,将母体吡啶转化为在特定位点带有多种取代基的苯和萘,这些取代基由环加成反应组分定义。证明了吡啶核心在多种药物中的后期骨骼多样化中的应用。
Iridium‐Catalyzed Reductive Strecker Reaction for Late‐Stage Amide and Lactam Cyanation
作者:Ángel L. Fuentes de Arriba、Elena Lenci、Mahendra Sonawane、Odilon Formery、Darren J. Dixon
DOI:10.1002/anie.201612367
日期:2017.3.20
A new iridium‐catalyzed reductive Strecker reaction for the direct and efficient formation of α‐amino nitrile products from a broad range of (hetero)aromatic and aliphatic tertiary amides, and N‐alkyl lactams is reported. The protocol exploits the mild and highly chemoselective reduction of the amide and lactam functionalities using IrCl(CO)[P(C6H5)3]2 (Vaska's complex) in the presence of tetramethyldisiloxane
报道了一种新的铱催化的还原斯特雷克反应,该反应可从多种(杂)芳族和脂肪族叔酰胺以及N-烷基内酰胺直接有效地形成α-氨基腈产物。该协议利用IrCl(CO)[P(C 6 H 5)3 ] 2利用酰胺和内酰胺官能团进行轻度和高度化学选择性还原(Vaska's complex)(Vaska's complex)在存在还原剂的四甲基二硅氧烷的情况下,直接生成可通过TMSCN(TMS =三甲基甲硅烷基)处理而被氰化物取代的半胱氨酸类物质。该方案操作简单,适用范围广,有效(最高收率99%),已成功应用于含酰胺和内酰胺的药物以及天然生物碱的后期功能化以及与二肽和三肽中脯氨酸残基的N原子连接的羰基碳原子的选择性氰化。