Nickel-Catalyzed Intermolecular [3 + 2 + 2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes. Synthesis of Seven-Membered Carbocycles
作者:Shinichi Saito、Shinsuke Komagawa、Isao Azumaya、Manami Masuda
DOI:10.1021/jo7014714
日期:2007.11.1
The [3 + 2 + 2] cocyclization of ethyl cyclopropylideneacetate (1a) and various alkynes proceeded smoothly in the presence of Ni(cod)2–PPh3. The cycloheptadiene derivatives were synthesized in highly selective manners. The unique reactivity of 1a was essential for the progress of the reaction. The observed regioselectivity of the product formation and the mechanism of the reaction are discussed.
在Ni(cod)2 -PPh 3的存在下,环丙叉基乙酸乙酯(1a)和各种炔烃的[3 + 2 + 2]共环化反应顺利进行。环庚二烯衍生物以高度选择性的方式合成。1a的独特反应性对于反应的进行至关重要。讨论了观察到的产物形成的区域选择性和反应机理。