An unprecedented [5,6]-open adduct via a direct benzyne-C-60 cycloaddition

作者：Kim Gyoungsik; Lee Kyu Cheol; Kim Jonggi; Lee Jungho; Lee Sang Myeon; Lee Jeong Chu; Seo Jung Hwa; Choi Won Youl; Yang Changduk^*

来源：Tetrahedron, 2013, 69(35): 7354-7359.

DOI：10.1016/j.tet.2013.06.073

• Buckminsterfullerene
• Benzyne
• [5,6]-Open adduct
• [6,6]-Closed adduct
• Cycloaddition

Cycloaddition is one of the best-studied types of reactions in the organic chemistry of fullerenes, engendering [6,6]-closed adducts in the vast majority of cases. Notwithstanding that a formation of open fulleroid structures is undoubtedly of theoretical interest, no one has demonstrated the conformation of [5,6]-open fulleroid via the direct cycloadditions. Here, we establish that cycloaddition between C-60 and benzyne in situ generated from 2-amino-4,5-dibutoxybenzoic acid affords a new type of elusive [5,6]-open structure that is characterized on the basis of NMR, UV-vis spectroscopy, and cyclic voltammetry. Additionally, from density functional theory (DFT) calculations for possible [5,6]-open and [6,6]-closed adducts induced of benzyne-C-60 reaction, as expected, features such as the charge distributions, binding characteristics, and frontier molecular orbital levels, are affected by the different binding modes in C-60 cage.

• 出版日期2013-9-2