Acetylenes as potential antarafacial components in concerted reactions. Formation of pyrroles from thermolyses of propargyl amines, of a dihydrofuran from a propargylic ether, and of an ethylidenepyrrolidine from a .beta.-amino acetylene
Acetylenes as potential antarafacial components in concerted reactions. Formation of pyrroles from thermolyses of propargyl amines, of a dihydrofuran from a propargylic ether, and of an ethylidenepyrrolidine from a .beta.-amino acetylene
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乙炔作为协同反应中潜在的反面成分。
DOI：
10.1021/jo00071a015
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发表时间：
1993
影响因子：
3.6
通讯作者：
J. S. Locke
中科院分区：
文献类型：
--
作者：
A. Viola;J. J. Collins;N. Filipp;J. S. Locke
炔属化合物的热环化提供了炔键在[2+2]过程中作为反面组分的能力的证据。环化反应与通常有利的炔逆烯反应竞争。炔丙基胺，没有取代基，其存在会阻碍一个紧密的环状过渡态，产生中间体吡咯啉，其随后的氢消除提供少量的吡咯。在2-乙炔基四氢吡喃中的相同方法以35%产率得到8-氧杂双环[3.2.1]辛烷。N-甲基-3-己炔-1-胺的相关热反应提供了在标称[2s +2a +2s +2s] Mobius过程中向N-甲基-2-亚乙基吡咯烷的定量转化，其中炔属单元是反面组分
A thermal cyclization of acetylenic compounds provides evidence for the ability of acetylenic links to act as antarafacial components in [2+2] processes. The cyclization competes with the normally favored acetylenic retro-ene reaction. Propargylic amines, without substituents whose presence would hinder a tight cyclic transition state, yield intermediate pyrrolines whose subsequent hydrogen elimination affords pyrroles in small amounts. The same process in 2-ethynyltetrahydropyran affords 8-oxabicyclo[3.2.1]octane in 35% yield. A related thermal reaction of N-methyl-3-hexyn-1-amine provides a quantitative transformation to N-methyl-2-ethylidenepyrrolidine in a nominal [2 s +2 a +2 s +2 s ] Mobius process, wherein the acetylenic unit is the antarafacial component