Formation of 4,5,6,7-Tetrahydroisoindoles by Palladium-Catalyzed Hydride Reduction
作者:Duen-Ren Hou、Ming-Shiang Wang、Ming-Wen Chung、Yih-Dar Hsieh、Hui-Hsu Gavin
DOI:10.1021/jo7016845
日期:2007.11.1
reduced to 4,5,6,7-tetrahydro-2H-isoindoles. Isoindole 24 was also reduced to a mixture of an isoindoline and a 4,5,6,7-tetrahydro-2H-isoindole. In contrast, 2,3-dihydro-1H-indoles 21 underwent dehydrogenation to give thermodynamically stable indoles. Theoretical calculations show the significant difference in aromaticity between isoindoles and indoles, corresponding to the observed differences in reactivities
制备了取代的1,3-二氢-2H-异吲哚(2,异吲哚啉),并进行了钯催化的甲酸还原。烷基异吲哚啉被还原为4,5,6,7-四氢-2H-异吲哚(1)。对于5-甲氧基异吲哚啉仅观察到部分还原,并且4-甲氧基-,5-碳甲氧基-,氨基和酰胺基异吲哚啉对该反应是惰性的。将卤素取代的异吲哚啉脱卤并还原为4,5,6,7-四氢-2H-异吲哚。异吲哚24也被还原为异吲哚啉和4,5,6,7-四氢-2H-异吲哚的混合物。相反,2,3-二氢-1 H-吲哚21进行脱氢反应得到热力学稳定的吲哚。理论计算表明,异吲哚和吲哚之间的芳香性存在显着差异,与观察到的反应性差异相对应。在NBS和空气存在下,将四氢-2 H-异吲哚1氧化为4,5,6,7-四氢异吲哚-1,3-二酮。