Efficient Mono- and Dilithiation of 2-Bromo-1,1-diphenylethene with n-Butyllithium/Tetramethylethylenediamine
作者:Sergei M. Korneev、Dieter E. Kaufmann
DOI:10.1055/s-2002-20963
日期:——
Lithiation of 2-bromo-1, 1-diphenylethene (2) with «-butyllithium or tert-butyllithium/tetramethylethylenediamine (TMEDA) in pentane at -100 °C effects a halogen-lithium exchange to give 2-lithio-1,1-diphenylethene (3) exclusively, which reacts with electrophiles to provide 2-substituted-1,1-diphenylethenes 5-8 in high yields. Further lithiation of the monolithium derivative 3 with n-butyllithium/TMEDA