过渡金属催化的定向C–H功能化已成为构建C–C键和C–N键的强大而直接的工具。在这些方法中,分子内环烯烃的氢芳基化反应受到了广泛的关注,因为这种分子内环化可以产生在许多天然产物和生物活性分子中发现的更复杂和高附加值的结构基序。尽管取得了显着进展,但迄今为止开发的这些环空方案仍仅限于烯烃一侧的氢芳基化和官能化,因此在很大程度上限制了结构的多样性和复杂性。在这里,我们开发了铑(III)催化的芳香族系链烯烃的串联环化芳基化/酰胺化反应,通过使用3-取代的1,4,2-二恶唑-5生成各种带有全碳四元立体中心的2,3-二氢-3-苯并呋喃甲胺衍生物-作为酰胺化试剂,用于捕获瞬态C(sp 3)-Rh中间体。值得注意的是,只需简单地改变导向基团,就可以实现第二次不对称的邻位C H酰胺化/环化反应,从而以高收率提供三环二氢呋喃并[3,2- f ]喹唑啉酮。
A cobalt(III)-catalyzed C-8 selective C–H amidation of quinoline N-oxide using dioxazolone as an amidating reagentundermildconditions is disclosed. The reaction proceeds efficiently with excellent functional group compatibility. The utility of the current method is demonstrated by gram scale synthesis of C-8 amide quinoline N-oxide and by converting this amidated product into functionalized quinolines
amidating reagent has been developed. This protocol is a simple, straightforward, and economic was to afford a variety of N-(2-(imidazo[1,2-a]pyridin-2-yl)phenyl)acetamide derivatives with excellent yields. A mechanistic study reveals that a reversible cleavage of C–H bond might be involved in the reaction.
已经开发了使用二恶唑酮作为酰胺化试剂的Rh(III)催化的2-芳基咪唑杂环的定向邻位酰胺化。该方案简单,直接且经济,目的是以优异的产率提供各种N-(2-(咪唑并[1,2 - a ]吡啶-2-基)苯基)乙酰胺衍生物。一项机理研究表明,该反应可能涉及C–H键的可逆裂解。
The Direct Rh(III)-Catalyzed C–H Amidation of Aniline Derivatives Using a Pyrimidine Directing Group: The Selective Solvent Controlled Synthesis of 1,2-Diaminobenzenes and Benzimidazoles
作者:Shrikant M. Khake、Naoto Chatani
DOI:10.1021/acs.orglett.0c01126
日期:2020.5.1
The regioselective Rh(III)-catalyzed C-Hamidation of aniline derivatives with dioxazolones as an amidating reagent with a pyrimidine as a directing group leading to the production of 1,2-diaminobenzene derivatives or benzimidazole derivatives is described. The product distribution is controlled by the nature of solvent used. The reaction provides a broad substrate scope for aniline derivatives with
Rhodium(III)-Catalyzed Directed C−H Amidation of <i>N</i>
-Nitrosoanilines and Subsequent Formation of 1,2-Disubstituted Benzimidazoles
作者:Yanyu Chen、Rong Zhang、Qiujun Peng、Lanting Xu、XianHua Pan
DOI:10.1002/asia.201701287
日期:2017.11.2
An efficient rhodium‐catalyzeddirectC−Hamidation of N‐nitrosoanilines with 1,4,2‐dioxazol‐5‐ones as amidating agents has been developed. This method featured mild reaction conditions, a wide substrate scope and satisfactory yields. Besides, the amidated products could be readily converted to pharmaceutically valuable 1,2‐disubstituted benzimidazoles via an HCl‐mediated deprotection/cyclization process
Diastereoselective Three-Component 3,4-Amino Oxygenation of 1,3-Dienes Catalyzed by a Cationic Heptamethylindenyl Rhodium(III) Complex
作者:Finn Burg、Tomislav Rovis
DOI:10.1021/jacs.1c09276
日期:2021.11.3
tool to rapidly access β-amino alcohols–a privilegedmotif ubiquitous in natural products, pharmaceuticals and agrochemicals. Although a variety of expedient methods are established for simple alkenes, selective amino oxygenation of 1,3-dienes is less explored. Within this context, methods for the oxyamination of 1,3-dienes that are selective for the internal position remain unprecedented. We herein report