Organic letters
Directed o rtho Metalation Approach to C-7-Substituted Indoles. Suzuki-Miyaura Cross Coupling and the Synthesis of Pyrrolophenanthridone Alkaloids
CG Hartung, A Fecher, B Chapell, V Snieckus
Index: Hartung, Christian G.; Fecher, Anja; Chapell, Brian; Snieckus, Victor Organic Letters, 2003 , vol. 5, # 11 p. 1899 - 1902
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Citation Number: 120
Abstract
Although the indole N-phosphinoyl derivative 4 undergoes n-BuLi deprotonation/ electrophile quench to afford C-7-substituted products, its deprotection requires harsh conditions. On the other hand, the N-amide 12, upon sequential or one-pot C-2 metalation, silylation, C-7 metalation, and electrophile treatment, furnishes indoles 7 in good overall yields. In combination with the Suzuki-Miyaura protocol, C-7 aryl (heteroaryl)-substituted ...