Divergent synthesis of multi-substituted phenanthrenes via an internal redox reaction/ring expansion sequence.

Autor:	Koyama R; Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan. k_mori@cc.tuat.ac.jp., Anada M; Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan.; Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan., Sueki S; Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan.; Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan., Makino K; Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan.; Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan., Kojima T; Department of Applied Chemistry, Kobe City College of Technology (KCCT), 8-3 Gakuen-Higashimachi, Nishi-ku, Kobe, 651-2194, Japan., Kawasaki-Takasuka T; Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan. k_mori@cc.tuat.ac.jp., Mori K; Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan. k_mori@cc.tuat.ac.jp.
Jazyk:	angličtina
Zdroj:	Chemical communications (Cambridge, England) [Chem Commun (Camb)] 2024 Apr 02; Vol. 60 (28), pp. 3822-3825. Date of Electronic Publication: 2024 Apr 02.
DOI:	10.1039/d4cc00797b
Abstrakt:	We report an effective synthetic route to multi-substituted phenanthrenes via an internal redox reaction/ring expansion sequence. The interesting feature of the present system is that it allows for the divergent synthesis of the target skeleton depending on the selected Lewis acid catalyst. When benzylidene malonates with a cyclic structure at the ortho -position were treated with BF 3 ·OEt 2 , three sequential processes (internal redox reaction/elimination of the alkoxy group/ring expansion) proceeded to give phenanthrene derivatives in which the alkoxycarbonyl (CO 2 R) group and the alkyl (R) group were in close proximity to each other, in good chemical yields. In sharp contrast, treatment with Bi(OTf) 3 exclusively led to the formation of another type of phenanthrene, whose R group was positioned distal to the CO 2 R group.
Databáze:	MEDLINE
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