Evaluate the comparative functional and mechanistic aspects of the Sandmeyer and Gattermann reaction — Haloalkanes and Haloarenes Chemistry Question
Question
Evaluate the comparative functional and mechanistic aspects of the Sandmeyer and Gattermann reactions. Which of the following analytical statements are chemically and practically true?
💡 Solution & Explanation
A) True. The expulsion of nitrogen gas is the ultimate enthalpic and entropic driver for both radical-based processes. B) True. The distinction lies in the physical state of the catalyst: solid $Cu(0)$ vs dissolved $Cu(I)$. C) False. The Sandmeyer reaction utilizing $CuCN$ and $KCN$ is the established, high-yield standard for synthesizing aryl nitriles. The Gattermann equivalent using highly volatile, lethal $HCN$ gas is extremely dangerous and rarely used due to vastly inferior yields. D) True. Neither reaction can introduce fluorine. Aryl fluorides uniquely require the precipitation and thermal decomposition of diazonium tetrafluoroborates (the Balz-Schiemann reaction).