Chemoselectivity in the Kosugi-Migita-Stille coupling of bromophenyl triflates and bromo-nitrophenyl triflates with (ethenyl)tributyltin was written by Ansari, Nurul N.;Cummings, Matthew M.;Soderberg, Bjorn C. G.. And the article was included in Tetrahedron in 2018.Reference of 76361-99-4 This article mentions the following:
Kosugi-Migita-Stille cross coupling reactions of (ethenyl)tributyltin with all isomeric permutations of bromophenyl triflate and bromo-nitrophenyl triflate were examined in order to determine the chemoselectivity of carbon-bromine vs. carbon-triflate bond coupling under different reaction conditions. In general, highly selective carbon-bromine bond cross couplings were observed for example bis(triphenylphosphine)palladium dichloride (2 mol %) in 1,4-dioxane at reflux. In contrast, reactions using the same pre-catalyst but in the presence of a three-fold excess of lithium chloride in N,N-dimethylformamide at ambient temperature were in most cases selective for coupling at the carbon-triflate bond. Overall, isolated yields and the selectivity for carbon-bromine bond coupling were significantly higher compared to carbon-triflate bond coupling. In the experiment, the researchers used many compounds, for example, 3-Bromo-2-nitrophenol (cas: 76361-99-4Reference of 76361-99-4).
3-Bromo-2-nitrophenol (cas: 76361-99-4) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. alpha-Bromoesters are employed in the Reformatsky reaction for the synthesis of beta-hydroxyesters. The principal reactions for organobromides include dehydrobromination, Grignard reactions, reductive coupling, and nucleophilic substitution.Reference of 76361-99-4
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary