Formation of Seven-Membered Carbocycles via 7-endo Mode Cyclization of Lithioheptatrienes
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- 作者：Ken-ichiro Kanno ; Eri Igarashi ; Yuki Mizukami ; Kiyohiko Nakajima ; Zhiyi Song ; Tamotsu Takahashi
- 刊名：Organic Letters
- 出版年：2016
- 出版时间：December 16, 2016
- 年：2016
- 卷：18
- 期：24
- 页码：6217-6219
- 全文大小：339K
- ISSN：1523-7052
文摘
The highly selective synthesis of triene derivatives was achieved by a zirconocene-mediated three-component coupling reaction, and the trienes were efficiently subjected to 7-endo mode cyclization. The reaction of unsymmetrical zirconacyclopentadienes prepared from two different alkynes with N-bromosuccinimide (NBS) followed by treatment with allyl halides in the presence of CuCl afforded the corresponding heptatrienes in good yields. When the trienes reacted with an organolithium reagent, 7-endo mode cyclization occurred smoothly to give the corresponding cycloheptadiene.