inexpensive, nontoxic manganese catalyst enabled unprecedented redox‐neutral carbonylative annulations under ambient pressure. The manganese catalyst outperformed all other typically used base and precious‐metal catalysts. The outstanding versatility of the manganese catalysis manifold was reflected by ample substrate scope, setting the stage for effective late‐stage manipulations under racemization‐free
heterocycles due to their wide range of bioactivities. An efficient silver-catalyzed intermolecular cyclization of 2-aminopyridines with various alkynoates has been developed. 2-Substituted 4H-pyrido[1,2-a]pyrimidin-4-ones containing a wide range of functional groups are synthesized in the standard conditions. This transformation is conducted under convenient conditions and affords products in good yields
嘧啶酮由于其广泛的生物活性而成为重要的含氮杂环之一。已经开发了有效的银催化的2-氨基吡啶与各种链烷酸酯的分子间环化。在标准条件下合成含有2-官能取代的4 H-吡啶并[1,2 - a ]嘧啶-4-酮。该转化是在方便的条件下进行的,并以高收率提供产物。
Metal free C-3 chalcogenation (sulfenylation and selenylation) of 4<i>H</i>-pyrido[1,2-<i>a</i>]pyrimidin-4-ones
作者:Prasanjit Ghosh、Gautam Chhetri、Sajal Das
DOI:10.1039/d1ra00834j
日期:——
An expeditious metal free C-3 chalcogenation of 4H-pyrido[1,2-a]pyrimidin-4-one has been devised to synthesize diversely orchestrated 3-ArS/ArSe derivatives in high yields (up to 95%). This operationally simple reaction proceeds under mild reaction conditions, can be executed in gram scale, and also highlights broad functional group tolerance. Preliminary experimental investigation suggests a radical
设计了 4 H -pyrido[1,2- a ]pyrimidin-4-one 的快速无金属 C-3 硫属化反应,以高产率(高达 95%)合成多种精心设计的 3-ArS/ArSe 衍生物。这种操作简单的反应在温和的反应条件下进行,可以以克级进行,并且还突出了广泛的官能团耐受性。初步实验研究表明了这些转变的根本机制途径。
[Bis(trifluoroacetoxy)iodo]benzene Mediated C‐3 Selenylation of Pyrido[1,2‐
<i>a</i>
]Pyrimidin‐4‐Ones Under Ambient Conditions
作者:Prasanjit Ghosh、Gautam Chhetri、Eliyahu Perl、Sajal Das
DOI:10.1002/adsc.202001426
日期:2021.4.13
[Bis(trifluoroacetoxy)iodo]benzene mediated C−H bond arylselenylation of 4H‐Pyrido‐[1,2‐a]‐Pyrimidin‐4‐ones using readily available organodiselenides. This methodology is scalable and permits for the generation of a broad spectrum of functionally and structurally diverse selenoether derivatives in very promising yields (up to 98%). Notably, this protocol proceeds at ambientconditions and in the absence of
本文中,我们报道了[Bis(三氟乙酰氧基)碘]苯介导的4 H-吡啶基-[1,2 - a ]-嘧啶-4-基的4 H-吡啶键芳基硒基化反应。这种方法学是可扩展的,并允许以非常有希望的产率(高达98%)产生功能上和结构上多样化的多种硒醚衍生物。值得注意的是,该方案在环境条件下并且在没有金属的情况下进行。还证明了该方法在轻松合成屁股取代的5 H-噻唑并吡啶[3,2 - a ]嘧啶-4-酮中的应用。
Visible Light Assisted Direct C3–H Arylation of Pyrido[1,2-<i>a</i>]pyrimidin-4-ones and Thiazolo[3,2-<i>a</i>]pyrimidin-5-ones
作者:Rajesh T. Bhawale、Umesh A. Kshirsagar
DOI:10.1021/acs.joc.3c00780
日期:2023.7.7
Metal-catalyst-free, organic dye-catalyzed C3–H arylation of pyrido[1,2-a]pyrimidin-4-ones using visible light irradiation was developed under mild reaction conditions. This operationally simple and direct C–H functionalization approach effectively produced biologically significant C3 arylated pyrido[1,2-a]pyrimidin-4-one and thiazolo[3,2-a]pyrimidin-5-one derivatives, including medicinally important
在温和的反应条件下,开发了使用可见光照射的无金属催化剂、有机染料催化的吡啶并[1,2- a ]嘧啶-4-酮的C3-H芳基化。这种操作简单且直接的C-H功能化方法有效地产生了具有生物学意义的C3芳基化吡啶并[1,2- a ]嘧啶-4-一和噻唑并[3,2- a ]嘧啶-5-一衍生物,包括医学上重要的内皮细胞功能障碍抑制剂和抗炎剂的产率良好至优异,且具有良好的官能团耐受性。目前的光诱导直接 C3-H 芳基化方法适合放大合成。