Rank the following compounds in order of increasing reactivity toward the nucleophilic hydride reagent,NaBH₄. A)I

Question

Rank the following compounds in order of increasing reactivity toward the nucleophilic hydride reagent,NaBH₄. A)I < II < III B)III < II < I C)II < III < I D)II < I < III

Quizplus · Accepted Answer

The reactivity of a compound towards a nucleophilic hydride reagent is mainly determined by the stability of the intermediate that forms during the reaction. Compounds that can stabilize negative charges or partial negative charges are more reactive towards nucleophilic hydride reagents. In this case, compound I has a positively charged nitrogen, which makes it less likely to react with a hydride. Compound III has an electron-withdrawing group (carbonyl) adjacent to the double bond, which stabilizes the partial negative charge that forms during the reaction, making it more reactive than I. However, compound II has a strongly electron-withdrawing group (nitrile) adjacent to the double bond, which stabilizes the negative charge even more, making it the most reactive towards the nucleophilic hydride reagent. Therefore, the correct order of reactivity is II < I < III, which corresponds to choice D.

Rank the Following Compounds in Order of Increasing Reactivity Toward