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Koo, S., Science of Synthesis, (2010) 45, 1406.
Commercially available tropylium tetrafluoroborate (184) readily reacts with organolithium reagents to 7-alkyl- or 7-aryl-substituted cyclohepta-1,3,5-trienes. 7-Methylcyclohepta-1,3,5-triene can be obtained (83% yield after distillation) by the reaction with methyllithium in diethyl ether.[191] Various aryllithium reagents which can be prepared in a regioselective manner add to tropylium salt 184 to afford polycyclic aromatic compounds containing a cycloheptatrienyl moiety (Scheme 45).[192–194] Selective monolithiation of 1,8-dibromonaphthalene with butyllithium provides (8-bromonaphthalen-1-yl)lithium (203), which reacts with 184 to give 1-bromo-8-(cyclohepta-2,4,6-trienyl)naphthalene (204) in 83% yield.[192] Deprotonation of 3-bromo-1-benzothiophene (205) with lithium diisopropylamide, followed by addition of 184 gives 3-bromo-2-(cyclohepta-2,4,6-trienyl)-1-benzothiophene (206) as expected,[193] whereas successive treatment of 2,3-dibromo-1-methyl-1H-indole (207) with tert-butyllithium and then with 184 abnormally generates 2-bromo-3-(cyclohepta-2,4,6-trienyl)-1-methyl-1H-indole (208).[194] It is plausible that the initially formed 3-bromo-2-lithio-1-methyl-1H-indole rearranges to 2-bromo-3-lithio-1-methyl-1H-indole before 184 is added.
Meeeee 88 Meeeeeee ee Meeeeeeeeeeee Meeeeeee ee Meeeeeeee Meeeeeeeeeeeeeeee[888–888]
Meeeeeeeeeee Meeeeeeee
8-Meeee-8-(eeeeeeeeee-8,8,8-eeeeeee)eeeeeeeeeee (888); Meeeeee Meeeeeeee:[888]
Me e eeeeeee eeee ee 8,8-eeeeeeeeeeeeeeeeee (8.888 e, 8.88 eeee) ee MMM (88 eM) eeeeee ee −88°M eee eeeee eeeeeeee eeee 8 eee e 8.88 M eeee ee MeMe ee eeeeee (8.88 eM, 8.88 eeee). Mee eeee eee eeeeeee ee −88°M eee 88 eee, eee eeeeeeeee eeeeeeeeeeeeeeeee (888; 8.888 e, 8.88 eeee) eee eeeee ee eee eeeeeee ee eeee e eeee eeeee eeeeeeeeee. Meee eeeeeee eee eeeeeee ee −88°M eee 8 e, ee 8°M eee 88 eee, eee ee ee eee 8 e, eee eeee eeeeeee eeee 88% MMe (88 eM). Mee eeeeeee eeee eee eeeeeeeee eeee Me8M (8 × 88 eM). Mee eeeeeeee eeeeeee eeee eee eeeeee eeee eee. MeMMM8 (88 eM) eee eeee 88% MeMe (8 × 88 eM), eeeee (MeMM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeee eeeeeee eee eeeeeeee ee MMMM (eeeeee); eeeee: 8.888 e (88%).
References
| [191] | Meeeee, M.; Meeeée, M.-M., Meeee. Meee., (8888) 888, 8888; Meeee. Meee. Mee. Me., (8888) 88, 8888. |
| [192] | Meeee, M.; Meeeeee, M.; Meeee, M.; Meeeeeee, M.-e., M. Mee. Meee., (8888) 88, 888. |
| [193] | Meeeeeee, M.; Meeee, M.; Meeeeeeee, M.; Meeeee, M.; Meeeeeee, M.; Meeee, M., Mee. Meeeee. Meee., (8888) 8, 8888. |
| [194] | Meee, M.; Meeeeeee, M.; Meeeeeeee, M.; Mee, M.; Meeeeeeee, M.; Meeeeeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 8/8e, 888.
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