Synthesis of corannulene and alkyl derivatives of corannulene

Synthesis of corannulene and alkyl corannulene derivatives has been accomplished using solution-phase chemistry. The key step in the synthesis is the coupling of benzylic bromides of 1,6,7,10-tetraalkylfluoranthene derivatives by low-valent titanium to construct the corannulene nucleus. The use of low-valent titanium represents a viable alternative to flash vacuum pyrolysis methods previously developed. Corannulene (1), methylcorannulene (8), three different dimethylcorannulenes (2, 3, 5), two different tetramethylcorannulenes (4, 6), acecorannulylene (7), C-5h symmetric pentamethylcorannulene (9), and decamethylcorannulene (10) have been prepared using low-valent titanium carbon-carbon coupling chemistry and halogen for alkyl exchange chemistry mediated by trimethylaluminum and catalytic nickel salts.