821773-98-2Relevant academic research and scientific papers
Unusual t-BuLi induced ortholithiation versus halogen-lithium exchange in bromopyridines: Two alternative strategies for functionalization
Pierrat, Philippe,Gros, Philippe,Fort, Yves
, p. 2319 - 2322 (2007/10/03)
The reaction of lithiating agents with various 3-bromopyridines has been investigated. An unprecedented selectivity was observed with t-BuLi, which effected a clean lithiation at C-4. With 3-bromo and 2-chloro-3-bromo pyridines, the ortholithiation-exchange ratio was strongly electrophile and addition order dependent while 2-chloro-5-bromopyridine always gave exclusive C-4 substitution.
