我们发现了双环氮杂芳烃的开环氟化。在用亲电氟化剂处理双环氮杂芳烃例如吡唑并[1,5- a ]吡啶时,芳环的氟化之后是开环反应。尽管这种整体转变可以归类为芳环的亲电氟化,但它是一种新型氟化,会导致叔碳氟键的构建。本方案可应用于一系列双环氮杂芳烃、耐受吖嗪和各种官能团。此外,还对机理研究和对映选择性氟化进行了检查。
Optimized scale up of 3-pyrimidinylpyrazolo[1,5-a]pyridine via Suzuki coupling; a general method of accessing a range of 3-(hetero)arylpyrazolo[1,5-a]pyridines
作者:Paul A. Bethel、Andrew D. Campbell、Frederick W. Goldberg、Paul D. Kemmitt、Gillian M. Lamont、Abid Suleman
DOI:10.1016/j.tet.2012.04.094
日期:2012.7
an improved synthesis of 3-(hetero)aryl pyrazolo[1,5-a]pyridines (such as 3-(2,5-dichloropyrimidin-4-yl)pyrazolo[1,5-a]pyridine (8)) via an optimized synthesis and Suzuki coupling of 3-pyrazolo[1,5-a]pyridine boronic ester 10. These conditions are applicable to both high throughput chemistry and large scale synthesis of these medicinally important compounds. The scope of this chemistry has been further
我们已经开发出3-(杂)芳基吡唑并[1,5- a ]吡啶(例如3-(2,5-二氯嘧啶-4-基)吡唑并[1,5- a ]吡啶(8)的合成方法。)通过优化的合成方法和3-pyrazolo [1,5- a ]吡啶硼酸酯10的Suzuki偶联。这些条件适用于这些医学上重要的化合物的高通量化学和大规模合成。该化学反应的范围已进一步扩展到包括新型硼酸酯3-(4,4,5,5-四甲基-1,3,2-二氧杂硼硼烷-2-基)-6,7的合成和偶联-二氢-5 H-吡唑并[5,1- b ] [1,3]恶嗪(43)。
Palladium-Catalyzed Regioselective Arylation of Pyrazolo[1,5-<i>a</i>]pyridines via C–H Activation and Synthetic Applications on P38 Kinase Inhibitors
A direct arylation of pyrazolo[1,5-a]pyridines with aryl iodides selectively occurring at the C-3 and C-7 positions via palladium-catalyzed C-H activation is described. In these reactions, (a) cesium(I) fluoride and (b) silver(I) carbonate were employed as the additive to afford 3- and 7-arylated pyrazolo[1,5-a]pyridines, respectively, in modest to good yields. These reactions showed good compatibility with functional groups, and the catalytic mechanisms of these reactions were proposed. Finally, the synthetic application on the potent p38 kinase inhibitors was demonstrated.
Cyclocarboamination of Alkynes with <i>N</i>-Aminopyridiniums by Photoredox Catalysis