Regiochemistry of [70]fullerene: preparation of C70(OOtBu)n (n = 2, 4, 6, 8, 10) through both equatorial and cyclopentadienyl addition modes.
[reaction: see text] tert-Butylperoxy radicals add to [70]fullerene to form a mixture of adducts C(70)(OO(t)()Bu)(n)() (n = 2, 4, 6, 8, 10). Four isomers were isolated for the bis-adduct with the two tert-butylperoxo groups attached at 1,2-, 5,6-, 7,23-, and 2,5-positions, respectively. Two isomers were isolated for the tetrakis-adduct with the tert-butylperoxo groups located along the equator in C(s)() symmetry and on the side in C(1) symmetry, respectively. Similarly, two isomers were isolated for the hexakis-adducts with a structure related to the tetrakis-adducts, one of which has the cyclopentadienyl substructure. No isomer was detected for the octakis- and decakis-adducts. The C(s)()-symmetric octakis- and C(2)-symmetric decakis-adducts have all the tert-butylperoxo groups located along the equator. The decakis-adduct is the major product under optimized conditions. The compounds were characterized by their spectroscopic data. Chemical correlation through further addition of tert-butylperoxy radicals to isolated pure derivatives confirmed the structure assignment. Mechanisms of the tert-butylperoxy radical addition to C(70) follow two pathways: equatorial addition along the belt and cyclopentadienyl addition on the side.
Xiao
Zuo
Z
Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Wang
Fudong
F
Huang
Shaohua
S
Gan
Liangbing
L
Zhou
Jiang
J
Yuan
Gu
G
Lu
Mujian
M
Pan
Jinqi
J
D003517:Cyclopentanes / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D008968:Molecular Conformation; D013237:Stereoisomerism
D003517:Cyclopentanes; D037741:Fullerenes