Synthesis and Mechanistic Study of Fused 2-Pyrrolines via Thermolysis of 6-Substituted-3,5-hexadienyl Azidoformates
作者:Pei-Lin Wu、Ta-Hsien Chung、Ying Chou
DOI:10.1021/jo010218j
日期:2001.10.1
6-substituted-3,5(Z)-hexadienyl azidoformates produced a cis and trans mixture. The mechanism was proposed as the loss of nitrogen to form an acyl nitrene, then addition to a double bond to produce an aziridine. Finally the cleavage of the C-C bond generated a vinylazomethine ylide followed by recyclization to a fused 2-pyrroline.
3,5-己二烯叠氮基甲酸酯在300摄氏度(0.05托)下的热分解会导致区域特异性地稠合的2-吡咯啉,无论C-3和C-4双键之间的构型E或Z如何。热解6-取代的3,5(E)-己二烯叠氮基甲酸酯生成动力学控制的2-吡咯啉,在H-1和H-8a之间具有顺式构型,而6-取代的3,5(Z)-己二烯叠氮基甲酸酯产生顺式和反式混合物。提出该机理为损失氮以形成酰基氮烯,然后加成双键以生成氮丙啶。最终,CC键的裂解产生乙烯基偶氮亚胺叶立德,然后再循环成稠合的2-吡咯啉。