665033-95-4Relevant academic research and scientific papers
Hg(OTf)2-catalyzed arylene cyclization
Namba, Kosuke,Yamamoto, Hirofumi,Sasaki, Ikuo,Mori, Kumiko,Imagawa, Hiroshi,Nishizawa, Muaio
supporting information; experimental part, p. 1767 - 1770 (2009/04/12)
Novel Hg(OTf)2-catalyzed arylene cyclization was achieved with highly efficient catalytic turnover (up to 200 times). The reaction takes place via protonation of allylic hydroxyl group by in situ formed TfOH of an organomercurlc intermediate to
Development of an Efficient Procedure for Indole Ring Synthesis from 2-Ethynylaniline Derivatives Catalyzed by Cu(II) Salts and Its Application to Natural Product Synthesis
Hiroya, Kou,Itoh, Shin,Sakamoto, Takao
, p. 1126 - 1136 (2007/10/03)
The development of efficient methods for the indole synthesis catalyzed by Cu(II) salts and its applications were investigated. Cu(OAc)2 has been proved to be the best catalyst for the synthesis of various 1-p-tolylsulfonyl or 1-methylsulfonylindoles, which have both electron-withdrawing and electron-donating groups on the aromatic ring and C2 position of indoles. For the primary aniline derivatives, Cu(OCOCF 3)2 showed good activities, while Cu(OAc)2 was a good catalyst for the cyclization of secondary anilines. This methodology could be applied to the sequential cyclization reaction for the compounds which have the electrophilic part in the same molecule. By prior treatment with KH, the sequential cyclization was realized to provide the tricyclic ring systems, but it was limited to five- and six-membered rings for the second cyclization. Finally, formal and total synthesis of hippadine with the Cu(II)-promoted indole synthesis as the key step was accomplished.
