Question
Stephen Buchwald synthesized several widely used dialkylbiaryl variants of these molecules for cross-coupling reactions. For 10 points each:
[10h] Name these functional groups that can drive enantioselective reactions while complexed with ferrocene scaffolds as a part of Josiphos ligands.
ANSWER: phosphines [accept diphosphines or triphosphines]
[10m] Triphenylphosphine is added to a secondary alcohol alongside DEAD and an ester in this SN2 reaction named after a Japanese chemist.
ANSWER: Mitsunobu reaction
[10e] Phosphines are also used to define the Tolman cone angle, which is used to quantify the degree of this effect displayed by a ligand. Bulky groups physically block atoms from interacting in this effect.
ANSWER: steric hindrance [or sterics or steric effects or steric resistance or steric factor or steric strain; prompt on strain]
<Chemistry>
Summary
| 2025 ACF Nationals | 04/19/2025 | Y | 3 | 30.00 | 100% | 100% | 100% |
Data
| Waterloo A | Georgia Tech | 10 | 10 | 10 | 30 |
| Chicago A | Stanford | 10 | 10 | 10 | 30 |
| Illinois A | Toronto A | 10 | 10 | 10 | 30 |