Electrochemical and H/D-labeling study of oxazolino[60]fullerene rearrangement.
Isomerization of an oxazoline cycle from a [6,6]- to [5,6]-junction on the C(60) sphere of dianionic [60]fullero-oxazoline (1(2-)) during a 1,4-addition is studied by electrochemistry and a stepwise addition of PhCH(2)Br and PhCD(2)Br. Cyclic voltammerty of the in situ generated 1(2-) shows a very unusual positive shift for the anodic peak corresponding to the oxidation of 1(2-), indicating that the C(60) cage of dianionic 1 bears only one unit negative charge due to the heterolytic cleavage of the C(60)-O bond. Further study with a stepwise addition of PhCH(2)Br and PhCD(2)Br, which are used to differentiate the aryl groups added at each step onto dianionic 1, shows explicitly there is an exclusive selectivity of the C-O bond for the ring-opening and ring-closure during the isomerization of the heterocycle. A reaction mechanism is proposed on the basis of the experimental results and computational calculations.
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin, China.
Wei-Wei
WW
Yang
Zong-Jun
ZJ
Li
Fang-Fang
FF
Li
Xiang
X
Gao