One-Pot Synthesis of Pyrazoles through a Four-Step Cascade Sequence
One-Pot Synthesis of Pyrazoles through a Four-Step Cascade Sequence
复制标题
通过四步级联序列一锅法合成吡唑
DOI：
10.1002/chem.201204322
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发表时间：
2013-04-01
影响因子：
4.3
通讯作者：
Zhan, Zhuang-Ping
中科院分区：
文献类型：
--
作者：
Hao, Lu;Hong, Jun-Jie;Zhan, Zhuang-Ping
以叔炔丙醇和对甲苯磺酰肼为原料，一锅法合成了3，4，5-和1，3，5-吡唑。吡唑是通过四步级联序列形成的，包括FeCl 3催化的炔丙取代、氮杂-迈耶舒斯特重排、碱基介导的6电环化和热[1，5] σ迁移。在该反应中，根据起始醇中的不同取代基，选择性地生成3，4，5-和1，3，5-吡唑。
A one-pot synthesis of 3,4,5- and 1,3,5-pyrazoles from tertiary propargylic alcohols and para-tolylsulfonohydrazide has been accomplished. The pyrazoles are formed through a four-step cascade sequence, including FeCl3-catalyzed propargylic substitution, aza-MeyerSchuster rearrangement, base-mediated 6electrocyclization, and thermal [1,5] sigmatropic shift. In this reaction, the 3,4,5- and 1,3,5-pyrazoles are produced selectively according to different substituents in the starting alcohols.