Lithiated Benzothiophenes and Benzofurans Require 2-Silyl Protection to Avoid Anion Migration - Hansen, Marvin M; Clayton, Marcella T; Godfrey, Alexander G; Grutsch Jr, John L; Keast, Sandra S; Kohlman, Dan T; McSpadden, Andreea R; Pedersen, Steven W; Ward, Jeffrey A; Xu, Yao-Chang (Synlett, 2004)