| 内容提要: |
Corannulene (C20H10) is the smallest non-planar fragment of C60.1 Because of its bowl-shaped structure, mono-substituted corannulene, if static, is a chiral compound (C1). At room temperature, corannulene undergoes a rapid, dynamic bowl inversion (2 × 105 s-1) through a planar transition state (C2v), which renders it into an achiral compound.2 Energy of activation for the bowl inversion of corannulene has been deduced experimentally as 11.5 kcal/mol.3 However, if two of the peri positions of corannulene are tethered together to form indenocorannulene, the inversion barrier becomes more than double. Therefore, the bowl-to-bowl inversion does not happen at room temperature. Both C-Fand C-Cl activation4,5 methodologies provide fruitful synthesis of chiral indenocorannulene derivatives. (Scheme 1.) C-Cl activation displays a general higher yield and greater functional group tolerance.
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