Direct Synthesis of Pyrazolo[5,1‐
<i>a</i>
]isoindoles
<i>via</i>
Intramolecular Palladium‐Catalyzed CH Bond Activation
作者:Young Lok Choi、Hyuk Lee、Bum Tae Kim、Kihang Choi、Jung‐Nyoung Heo
DOI:10.1002/adsc.201000260
日期:2010.10.9
An efficient, direct synthesis of pyrazolo[5,1-a]isoindoles employing a palladium-catalyzed intramolecular CH bond activation of 1-(2-halobenzyl)pyrazoles has been developed. The use of lithium chloride (LiCl) was found to be essential in these reactions, to suppress further CH bond activation at the C-3 position of pyrazolo[5,1-a]isoindole, when C-3 is unsubstituted. This protocol can be applied to
已经开发出一种有效的直接合成吡唑并[5,1- a ]异吲哚的方法,该方法利用钯催化的1-(2-卤代苄基)吡唑的分子内CH键活化作用。发现在这些反应中必须使用氯化锂(LiCl),以抑制当C-3未取代时在吡唑并[5,1- a ]异吲哚的C-3位置的进一步CH键活化。该方案可用于通过顺序的分子内和分子间CH键活化合成具有六元中心环系统的吡唑并[5,1- a ]异喹啉和完全取代的吡唑并[5,1- a ]异吲哚。