Hayashi Kazuhiko
College of Pharmacy, Kinjo Gakuin University, Moriyama-ku, Nagoya, Japan.
Yakugaku Zasshi. 2010 Oct;130(10):1339-46. doi: 10.1248/yakushi.130.1339.
1-Azabicyclo [1.1.0] butane (ABB) bearing the highly strained bicyclic structure, which is synthetically useful for the preparation of 3-substituted azetidines, was obtained by the cyclization of 2,3-dibromopropylamine hydrobromide derived from inexpensive allylamine only with organolithium compounds and lithium amides. When other bases were employed, such as potassium, sodium, and magnesium species, the reaction yielded almost no ABB. It was speculated that a lithium cation played an important role in the cyclization. Thus, we proposed that this reaction proceeded by the consecutive cyclization to aziridines via the SN2 process involving the activation of the C-Br bond based on the intermolecular Br…Li(+) coordination, as a result of studies of reaction mechanisms.
1-氮杂双环[1.1.0]丁烷（ABB）具有高度张力的双环结构，对制备3-取代氮杂环丁烷具有合成用途，它是由仅从廉价烯丙胺衍生而来的2,3-二溴丙胺氢溴酸盐仅与有机锂化合物和锂酰胺环化得到的。当使用其他碱，如钾、钠和镁类碱时，反应几乎不生成ABB。据推测，锂阳离子在环化过程中起重要作用。因此，基于反应机理的研究，我们提出该反应是通过分子间Br…Li(+)配位激活C-Br键，经由SN2过程连续环化为氮丙啶而进行的。
