Lithiated benzothiophenes and benzofurans require 2-silyl protection to avoid anion migration was written by Hansen, Marvin M.;Clayton, Marcella T.;Godfrey, Alexander G.;Grutsch, John L. Jr.;Keast, Sandra S.;Kohlman, Dan T.;McSpadden, Andreea R.;Pedersen, Steven W.;Ward, Jeffrey A.;Xu, Yao-Chang. And the article was included in Synlett in 2004.Product Details of 253429-31-1 This article mentions the following:
2-Trimethylsilyl protection of benzothiophenes and benzofurans prevents anion migration to the 2-position when lithiated species are formed. These lithiated benzothiophenes and benzofurans provide superior results in additions to piperidones. Deprotection is conveniently achieved under acidic conditions. Direct C-7 metalation of benzothiophene is enabled by 2-triisopropylsilyl protection at C-2. In the experiment, the researchers used many compounds, for example, 7-Bromo-4-fluorobenzofuran (cas: 253429-31-1Product Details of 253429-31-1).
7-Bromo-4-fluorobenzofuran (cas: 253429-31-1) belongs to benzofurans derivatives. Benzofurans are only weakly aromatic in nature and they are cleaved by many oxidative and reductive conditions. As benzofurans are prone to undergo ring opening of the heterocycle, examples of reduction of this type of aromatics by using dissolving metals are rather scarce.Product Details of 253429-31-1
Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem