9.4 Reduction of Alkynes
CHECK OUT CHAD'S
PRE-HEALTH PREP
PRE-HEALTH PREP
Table of Contents
Add a header to begin generating the table of contents
Catalytic Hydrogenation
| Less Substituted | More Substituted | |
|---|---|---|
| Two Groups Added | | |
| Reagents | H2 / catalyst catalyst = Pt, Pd, or Ni | |
| Regioselectivity | n/a | |
| Stereospecificity | Syn | |
| Other Characteristics | Adds 2 equivalents of H2. Same reagents as with alkenes. | |
Catalytic Hydrogenation with a Poisoned Catalyst (like Lindlar's Catalyst)
| Less Substituted | More Substituted | |
|---|---|---|
| Two Groups Added | | |
| Reagents | H2 / Lindlar’s catalyst Lindlar’s catalyst = Pd / BaSO4 / quinoline | |
| Regioselectivity | n/a | |
| Stereospecificity | Syn (forms a cis-alkene) | |
| Other Characteristics | Adds only 1 equivalent of H2. Unreactive with alkenes. | |
Dissolving Metal Reduction
| Less Substituted | More Substituted | |
|---|---|---|
| Two Groups Added | | |
| Reagents | Na / NH3(l) Works with Na, Li, or K | |
| Regioselectivity | n/a | |
| Stereospecificity | Anti (forms a trans-alkene) | |
| Other Characteristics | Adds only 1 equivalent of H2. Unreactive with alkenes. | |
