Synlett

A mild and effective method to synthesize carbazolones by CuI/L-proline-catalyzed intramolecular arylation

S Yan, H Wu, N Wu, Y Jiang

Index: Yan, Shaoyu; Wu, Haihong; Wu, Nan; Jiang, Yongwen Synlett, 2007 , # 17 p. 2699 - 2702

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Citation Number: 12

Abstract

The intramolecular cyclization was first conducted on N-2-iodoaryl enaminone 4a catalyzed by 10 mol% CuI and 20 mol% l-proline. This reaction proceeded well at 70 °C in DMSO in the presence of K 2 CO 3 to produce carbazolone 3a in 58% yield (Table [1] , entry 1). Higher yields were observed by raising the reaction temperature (entries 2-4). Among the bases tested, KOH gave the best result (entry 7). However, Cs 2 CO 3 and NaOH provided slightly lower yields (entries 5 ...