Microwave-Promoted Synthesis of<i>N</i>-Heterocycles by Tandem Imination/Annulation of γ- and δ-Ketoalkynes in the Presence of Ammonia
作者:Maria Alfonsi、Monica Dell'Acqua、Diego Facoetti、Antonio Arcadi、Giorgio Abbiati、Elisabetta Rossi
DOI:10.1002/ejoc.200900014
日期:2009.6
The synthesis of 3-substituted 1-methylpyrrolo[1,2-a]pyrazines and 3-substituted isoquinolines was achieved by the intramolecular cyclisation of 2-acetyl-1-propargylpyrroles and 2-alkynylbenzaldehydes, respectively, in the presence of ammonia under microwave heating. The tandem imination/annulation of 2-alkynylbenzaldehydes was easily accomplished under standard conditions, while TiCl4 was used to
3-取代的1-甲基吡咯并[1,2-a]吡嗪和3-取代的异喹啉的合成是通过2-乙酰基-1-炔丙基吡咯和2-炔基苯甲醛在氨的存在下在微波下分子内环化而实现的加热。2-炔基苯甲醛的串联亚胺化/环化在标准条件下很容易实现,而 TiCl4 用于实现吡咯并 [1,2-a] 吡嗪。在理论计算和光谱数据的基础上讨论了反应机理和区域选择性。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)