out, and the expected bridged compound (13) was afforded. Subsequently, the construction of fourth and fifth bridges in [4][32](1,3,4)ferrocenophane (16) was attempted by applying the working hypothesis in order to obtain perbridged [4][34](1,2,3,4,5)ferrocenophane (5). Both bridging reactions occurred as expected, and the synthesis of 5 was achieved. The absorption spectrum of 5 showed d–d* absorption
Selective Oxidation of the α-Methylene of the Bridge in Ferrocenophanes with Silver Oxide or Silver Perchlorate/Sodium Methoxide
作者:Masao Hisatome、Jun Watanabe、Koji Yamakawa
DOI:10.1246/bcsj.67.280
日期:1994.1
The treatment of ferrocenophanes with AgO, Ag2O or AgClO4/CH3ONa in methanol gave oxidized products at the α-methylene of the bridge. In the reaction of [m][n]ferrocenophanes (m, n = 3, 4, 5; m > n), the α-methylene of the longest bridge [m] was oxidized in preference to that of the shorter bridge [n]. A reaction mechanism via a radical and/or cation species on the α-methylene of the bridge is proposed
The bridge contraction of α-oxo[4]ferrocenophane via a Wolff rearrangement was examined; β-formylation with ethyl formate, diazotization with tosyl azide and then irradiation with a mercury lamp in ethanol gave α-ethoxycarbonyl[3]ferrocenophane. A sequence of the reactions was applied to di- and tribridged α-oxo[4]ferrocenophanes to afford the corresponding [3]ferrocenophanes. The same reaction of