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Cover Picture: Palladium‐Catalyzed Double Ullmann Reaction: An Approach towards Tetraphenylenes (Asian J. Org. Chem. 1/2016)
Author(s) -
Li Xin,
Han JianWei,
Wong Henry N. C.
Publication year - 2016
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.201500376
Subject(s) - chemistry , palladium , catalysis , cover (algebra) , organic chemistry , mechanical engineering , engineering
Tetraphenylene is non‐planar , featuring a distinct saddle‐shape structure with a central eight‐membered rigid ring. Structurally, the four benzene rings are ortho ‐annelated to form a central octagon, in which two opposite pairs of benzene rings are oriented above or below the average plane of the molecule. The picture is intended to explain the unique structure of tetraphenylene. A planar octagonal‐shape paddy field is shown in the background, which was used during the Southern Song Dynasty (1127‐1279) and it can still be seen in Hangzhou, China. The crystal structure of tetramethoxytetraphenylene, one of the target product described in this paper, is like a flying eagle. Furthermore, the palladium‐catalyzed double Ullmann coupling reactions for the preparation of tetraphenylenes are also shown in the picture. More information can be found in the full paper by H. Wong et al. on page 74 in Issue 1, 2016 (DOI: 10.1002/ajoc.201500327).