New efficient, flexible and regioselective synthesis of 2,4-di- and 2,3,4-trialkylated and arylated 1H-pyrroles

被引:0
|
作者
Enders, D
Maassen, R
Han, SH
机构
来源
LIEBIGS ANNALEN | 1996年 / 10期
关键词
1H-pyrroles; N-N bond cleavage; a(2)-umpolung; nucleophilic substitution; 2-acetoxy aldehyde dimethylhydrazones; titanium tetrachloride activation;
D O I
暂无
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Starting from easily available 2-acetoxy aldehyde dimethylhydrazones rac-2, we prepared various alkyl- and aryl-substituted 1H-pyrroles 6 in good overall yield. The titanium-mediated a(2)-umpolung reaction of rac-2 with different acyclic and cyclic silyl enol ethers 3 leads directly or via 4-oxo hydrazones rac,anti-4 to 1-(dimethylamino)-1H-pyrroles 5. A novel method for the reductive removal of the dimethylamino group affording 1H-pyrroles 6 is presented.
引用
收藏
页码:1565 / 1574
页数:10
相关论文
共 50 条