Poly(phosphoric acid) (PPA)-Promoted 5-exo-Cyclization of Iminium Ions Generated In Situ: A Facile Access to Functionalized Indene Derivatives
Yi-Fan Zhu, Xin-Le Geng, Yong-Hong Guan, Wei Teng, Xiaohui Fan*
*School of Chemical and Biological Engineering, Lanzhou
Jiaotong University, Lanzhou 730070, P. R. of China,
Email: fanxh
mail.lzjtu.cn
Y. Fan, B. Zhou, K. Chen, B. Wang, X. Li, X. Xu, Synlett, 2017, 28, 1657-1659.
DOI: 10.1055/s-0036-1589009
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Abstract
A simple and atom-economical, metal-free Brønsted acid promoted two-component reaction between cinnamaldehydes and sulfonamides provides a range of functionalized indenes from easily available starting materials. The resulting N-indenylsulfonamides can be converted into the corresponding indenylenamines or indanones.
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Key Words
indenes, iminium ions, indanones, exocyclization, polyphosphoric acid, cascade reaction
ID: J60-Y2017
