New Efficient, Flexible and Regioselective Synthesis of 2,4-Di- and 2,3,4-Trialkylated an Arylated 1H-Pyrroles
作者:Dieter Enders、Ralf Maaßen、Sin-Ho Han
DOI:10.1002/jlac.199619961011
日期:1996.10
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 titariummediated a2-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
从容易获得的2-乙酰氧基醛二甲基hydrrac - 2开始,我们以良好的总收率制备了各种烷基和芳基取代的1 H-吡咯6。钛介导的rac - 2与不同的无环和环状甲硅烷基烯醇醚3的2--聚甲醛反应直接或通过4-氧代rac,anti - 4生成1-(二甲基氨基)-1 H-吡咯5。提出了一种新的还原还原二甲氨基基团的方法,得到1 H-吡咯6。