Question
The cyto·toxicity of this ion prompted Carolyn Bertozzi to develop an alkyne-azide click reaction that was promoted by strain instead. For 10 points each:
[10m] Name this metal ion and its oxidation state. Because this reduced ion oxidizes rapidly in air, cells protect it inside proteins like superoxide dis·mutase and hemo·cyanin.
ANSWER: copper (I) (“copper one”) [or copper plus one; or copper one plus; or Cu+ or Cu+1 or Cu1+; or cuprous copper ion; reject “copper two plus,” “copper plus two,” “Cu2+,” “Cu+2,” or “cupric copper”; prompt on copper or Cu by asking “what oxidation state?”]
[10e] Though it’s often catalyzed by copper in organic chemistry, this reaction is run copper-free to label molecules in living cells. This reaction is the 4 + 2 (“four plus two”) cycloaddition of a diene and a dieno·phile.
ANSWER: Diels–Alder reaction [accept inverse-electron demand Diels–Alder reaction or IED Diels–Alder reaction or retro-Diels–Alder reaction]
[10h] Another metal-free bioconjugation links thiols to this compound — for instance, to install chemo·therapeutic drugs onto antibodies. This five-membered heterocycle clicks onto furan in a popular Diels–Alder co-polymerization.
ANSWER: maleimide (“muh-LAY-uh-myde”) [or 2,5-pyrroledione]
<Chemistry>
Summary
| 2023 ACF Nationals | 04/22/2023 | Y | 12 | 12.50 | 100% | 25% | 0% |
Data
| WUSTL A | Chicago B | 0 | 10 | 0 | 10 |
| Columbia A | Minnesota A | 10 | 10 | 0 | 20 |
| Illinois A | McGill A | 0 | 10 | 0 | 10 |
| Chicago A | Stanford A | 0 | 10 | 0 | 10 |
| MIT A | Texas A | 0 | 10 | 0 | 10 |
| Harvard A | Northwestern A | 10 | 10 | 0 | 20 |
| Toronto A | North Carolina A | 0 | 10 | 0 | 10 |
| Indiana A | Chicago C | 0 | 10 | 0 | 10 |
| Florida A | Duke A | 0 | 10 | 0 | 10 |
| Georgia Tech A | Yale A | 0 | 10 | 0 | 10 |
| WUSTL B | Penn A | 0 | 10 | 0 | 10 |
| Cornell B | UC Berkeley A | 10 | 10 | 0 | 20 |