title: Regioselective oxazolination of C70(2-) and formation of cis-1 C70 adduct with respect to the apical pentagon.
abstract: Oxazolination of C(70) has been achieved via the aerobic oxidation of C(70)(2-) in the presence of PhCN. Only one C(70) oxazoline regioisomer (1) is obtained, indicating that the oxazolination of C(70)(2-) occurs with an unusual regioselectivity. Further benzylation of 1(2-) with benzyl bromide leads to the formation of the first cis-1 C(70) derivative with respect to the apical pentagon (2), as shown by the X-ray single-crystal structure and various spectral characterizations. The structure of the obtained C(70) oxazoline (1) is resolved with H/D labeling benzylation and HMBC (heteronuclear multiple bond coherence) NMR on the basis of the structure of 2. The result shows that for compound 1, the O atom is selectively bonded to the C1, while the N atom is bonded to the C2 of C(70). The exhibited regioselectivity for the orientation of oxazolino group on C(70) is further rationalized with computational calculations, and a reaction mechanism for the oxazolination of C(70)(2-) is proposed.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Ni
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Yang
authors.forename: Zong-Jun
authors.initials: ZJ
authors.lastname: Li
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao