An “on water” palladium-catalyzed direct (hetero)arylation of 2H-pyrazolo[3,4-b]pyridines has been developed. The reactions proceeds smoothly with at low catalytic loading at low temperature providing the C3 (hetero)arylated products in good to excellent isolated yields. Free NH 3-arylated 7-azaindazoles were also prepared by simple cleavage of the N-protected groups.

中文翻译：

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2 H-吡唑并[3,4- b ]吡啶的“在水上”直接C-3芳基化

已经开发了2 H-吡唑并[3,4- b ]吡啶的“水上”钯催化的直接（杂）芳基化反应。反应在低温下以低催化负荷顺利进行，从而使C3（杂）芳基化产物的分离收率良好，甚至极佳。还可以通过简单裂解N-保护基团来制备游离的NH 3-芳基化的7-氮杂吲唑。