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。
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。
Suzuki–Miyaura cross-coupling reactions of halo derivatives of 4H-pyrido[1,2-a]pyrimidin-4-ones
cross-coupling reactions of halo derivatives of 4H-pyrido[1,2-a]pyrimidin-4-one with (het)arylboronic acids allow easy access to (het)aryl and vinyl derivatives of this bicycle in good to excellent yields, even from chloro derivatives. The sequence of reactivity of the halogen in the different positions of the ring system was also investigated. 6-Phenyl-4H-pyrido[1,2-a]pyrimidin-4-one could be prepared by thermal
钯催化的卤素衍生物的Suzuki-Miyaura交叉偶联反应 4 H-吡啶并[1,2- a ]嘧啶-4-一与(杂)芳基硼酸一起使用,即使从氯代衍生物中也可以很容易地获得该自行车的(杂)芳基和乙烯基衍生物。还研究了卤素在环系统不同位置的反应顺序。6-苯基-4 H-吡啶并[1,2- a ]嘧啶-4-一 可以通过热环化制备 异亚丙基(6-苯基吡啶-2-基氨基)亚甲基丙二酸酯,以及少量的7-苯基-1,4-二氢-1,8-萘啶-4-酮。
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。
New efficient approach for the synthesis of 2-alkyl(aryl) substituted 4<i>H</i>-pyrido[1,2-<i>a</i>]pyrimidin-4-ones
作者:Helio G. Bonacorso、Fernando J. Righi、Isadora R. Rodrigues、Cleber A. Cechinel、Michelle B. Costa、Arci D. Wastowski、Marcos A. P. Martins、Nilo Zanatta
DOI:10.1002/jhet.5570430136
日期:2006.1
A new, efficient and easy route for the preparation of a series of 2-alkyl(aryl) substituted 4-oxo-4H-pyrido-[1,2-a]pyrimidines, where alkyl = CH3; aryl = C6H5, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-CH3C6H4, 4-OCH3C6H4, 4-NO2C6H4 in 45–80 % yield from the reaction of β-alkoxyvinyl trichloromethyl ketones with 2-aminopyridine under mild conditions, is then reported.
一系列2-烷基(芳基)的制备一种新的,有效的和简单的路线被取代的4-氧代-4- ħ -pyrido- [1,2一]嘧啶类,其中烷基= CH 3 ; 芳= C 6 H ^ 5,4-FC 6 H ^ 4,4-CLC 6 ħ 4,4- BRC 6 ħ 4,4-CH 3 C ^ 6 ħ 4,4-OCH 3 C ^ 6 ħ 4,4-NO 2 C 6高4 据报道,在温和的条件下,β-烷氧基乙烯基三氯甲基酮与2-氨基吡啶的反应收率为45-80%。