Heterocycles

Optional Synthesis of 2-or 5-Substituted 3-Bromopyrroles via Bromine-Lithium Exchange of N-Benzenesulfonyl-2, 4-dibromopyrrole

T Fukuda, M Iwao

文献索引：Fukuda, Tsutomu; Iwao, Masatomo Heterocycles, 2012 , vol. 86, # 2 p. 1261 - 1273

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被引用次数: 3

摘要

The regioselective bromine–lithium exchange of N-benzenesulfonyl-2, 4-dibromopyrrole (6) with n-BuLi followed by treatment with various electrophiles gave 5-substituted 3- bromopyrroles (5) in excellent yields. In contrast, the sequential treatment of 6 with n-BuLi and diisopropylamine followed by quenching with electrophiles produced regioisomeric 2- substituted 3-bromopyrroles (3) selectively. The latter reaction can be rationalized by the ...