Synthesis of 2-Alkylidenepyrrolidines, Pyrroles, and Indoles by Condensation of Silyl Enol Ethers and 1,3-Bis-Silyl Enol Ethers with 1-Azido-2,2-dimethoxyethane and Subsequent Reductive Cyclization
作者:Esen Bellur、Helmar Görls、Peter Langer
DOI:10.1021/jo047856x
日期:2005.6.1
The condensation of 1,3-bis-silyl enol ethers with 1-azido-2,2-dimethoxyethane and subsequent reductive cyclization allowed an efficient regio- and diastereoselective synthesis of a variety of 2-alkylidene-4-methoxypyrrolidines. The thermal elimination of methanol resulted in the formation of functionalized pyrroles. Similarly, 2,3,3a,4,5,6-hexahydro-2,3-benzopyrroles were prepared and transformed
1,3-双甲硅烷基烯醇醚与1-叠氮基-2,2-二甲氧基乙烷的缩合和随后的还原环化使得各种2-亚烷基-4-甲氧基吡咯烷的区域和非对映选择性合成成为可能。甲醇的热消除导致官能化吡咯的形成。类似地,制备了2,3,3a,4,5,6-六氢-2,3-苯并吡咯并转化为4,5,6,7-四氢-2,3-苯并吡咯。相反,用三氟乙酸处理2-亚烷基亚吡咯烷导致通过[4 + 2]环加成形成吲哚并随后挤出氮原子。