Addition of dihalocarbenes to corannulene. A fullerene-type reaction

Dihalocarbenes (:CCl2,:CBr2, and :CI2) add preferentially to one of the rad ial double bonds of corannulene, rather than to the rim. These cyclopropana tions strongly resemble the additions of dihalocarbenes to fullerenes, whic h likewise occur at 6:6-double bonds, destroy the cyclic conjugation in two adjacent benzene rings, and give 'closed' adducts. An explanation is offer ed for the abnormally high reactivity of the interior carbon atoms of coran nulene. (C) 2000 Elsevier Science Ltd. All rights reserved.