Synthesis of imidazo[1,5-a]pyridines via I2-mediated sp3 C-H amination
Synthesis of imidazo[1,5-a]pyridines via I2-mediated sp3 C-H amination
复制标题
通过 I-2 介导的 sp(3) C-H 胺化合成咪唑并[1,5-a]吡啶
DOI：
10.1039/c8ob01501e
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发表时间：
2018-08-21
影响因子：
3.2
通讯作者：
Chang, Junbiao
中科院分区：
文献类型：
--
作者：
Hu, Zhiyuan;Hou, Jiao;Chang, Junbiao
以2-吡啶酮和烷基胺为原料，采用分子碘，建立了无过渡金属的sp（3）C-H胺化反应合成咪唑并[1，5-a]吡啶的方法。在乙酸钠（NaOAc）存在下，I-2介导的易获得的底物的氧化成环反应以一锅法有效地产生了多种咪唑并[1，5-a]吡啶衍生物。本合成方法操作简单，可方便地在克级规模上进行。此外，在最佳反应条件下，以相应的二-2-吡啶酮和取代苄胺为原料，以满意的产率合成了一系列1-（2-吡啶基）咪唑并[1，5-a]吡啶半胱氨酸蛋白酶抑制剂。
A transition-metal-free sp(3) C-H amination reaction has been established for imidazo[1,5-a] pyridine synthesis employing molecular iodine from 2-pyridyl ketones and alkylamines. In the presence of sodium acetate (NaOAc), the I-2-mediated oxidative annulations of readily available substrates produced a variety of imidazo[1,5-a] pyridine derivatives efficiently in a one-pot manner. The present synthetic approach is operationally simple and can be conveniently carried out on a gram scale. Moreover, under the optimal reaction conditions a series of 1-(2-pyridyl) imidazo[1,5-a] pyridine cysteine protease inhibitors were easily prepared from the corresponding di-2-pyridyl ketones and substituted benzylamines in satisfactory yields.