Corannulene. A Three-Step Synthesis¹

Abstract

Thermal cyclization of 7,10-diethynylfluoranthene ( 3 ) in the gas phase gives corannulene ( 2 ), the smallest bowl-shaped polycyclic hydrocarbon fragment of C 60 with fullerene-like curvature. Bromocorannulene ( 10 ) and 1,6-dibromocorannulene ( 9 ) have also been obtained from flash pyrolysis of 7,10-bis(2,2-dibromovinyl)fluoranthene ( 8 ). Short, practical syntheses of several corannulene precursors from acenaphthenequinone are described which have made corannulene available in gram quantities.