Synthesis of corannulene and alkyl derivatives of corannulene

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