Final answer:
Iodide (I-), thiolates (-SH), and cyanide (-CN) ions can react with an unspecified reactant denoted as ‘Br‘(3) in polar aprotic solvents due to their nucleophilic nature in SN2 reactions.
Step-by-step explanation:
The question is asking which of the given compounds can react with an unspecified reactant denoted as ‘Br‘(3) in polar aprotic solvents. As a nucleophilic reagent, the ion iodide (I-) or species with sulfhydryl (-SH) or cyano (-CN) groups are candidates for such reactions because they contain atoms with lone pairs that can act as nucleophiles. Acetone and DMF are solvent examples and would not typically react in the context of what is likely meant by ‘Br‘(3), as they are more commonly used as solvent media for such reactions.Polar aprotic solvents like DMF and acetonitrile are known for their ability to enhance the reactivity of nucleophiles in SN2 reactions by solvating cations while leaving anions relatively free to attack electrophilic centers. Iodide (I-), thiolates (-SH), and cyanide (-CN) ions are strong nucleophiles that can participate in SN2 reactions readily, especially in polar aprotic solvents.