1757-29-5Relevant articles and documents
Lithiations of 1-Trialkylsilylpyrroles: N to C Silyl Group Rearrangement
Chadwick, Derek J.,Hodgson, Simon T.
, p. 1833 - 1836 (2007/10/02)
The sites of metallation with alkyl-lithium reagents of 1-trimethylsilyl- and 1-triethylsilyl-pyrroles have been explored under a variety of conditions.With short reaction times, BunLi reacts with 1-trimethylsilylpyrrole in hexane predominantly at the 2-position though with ButLi in pentane the unusual 3-metallated product is preferred.During prolonged reaction of 1-trimethylsilyl- and 1-triethylsilyl-pyrroles with ButLi, the 2-monolithio- and the 2,4- and 2,5-dilithio-intermediates are formed, in which, unexpectedly, the silyl groups migrate to the pyrrole 2-position.Under conditions favouring enhanced ionicity, BunLi cleaves the N-SiMe3 bond in preference to ring metallation.