Abstract
En pålitlig, mellan skala framställning av 1,2,3,4,5-pentamethylcyclopentadiene (Cp * H) presenteras, baserade på ändringar av befintliga protokoll som härrör från den första 2-bromo-2-buten litiering följt av syra-medierad dienol cyklisering . Den reviderade syntes och rening av liganden undviker användningen av mekanisk omrörning medan de låter tillgång till signifikanta mängder (39 g) av Cp * H i gott utbyte (58%). Förfarandet ger ytterligare andra fördelar, bland annat en mer kontrollerad släcka av överskott litium under framställningen av mellan heptadienols och en förenklad isolering av Cp * H med tillräcklig renhet för metallisering med övergångsmetaller. Liganden användes därefter för att syntetisera [Cp * MCI 2] 2-komplex av både iridium och rutenium att demonstrera användbarheten av Cp * H framställes och renas enligt vår metod. Det förfarande som beskrivs häri ger väsentliga mängder av en allmänt förekommande underordnad ligand support som används i metallorganisk kemi och samtidigt minimera behovet av specialiserad laboratorieutrustning, vilket ger en enklare och mer lättillgänglig ingångspunkt i kemi 1,2,3,4,5-pentamethylcyclopentadiene.
Materials
| Name | Company | Catalog Number | Comments |
| Materials | |||
| Lithium wire (in mineral oil) | Aldrich | 278327-100G | >98% |
| 2-bromo-2-butene (mixture of cis/trans isomers) | Acros | 200016-364 | 98%, dried over molecular sieves from an oven overnight before use |
| Hexanes | Millipore | HX0299-3 | GR ACS, used as received |
| Ethyl actetate | Millipore | EX0240-3 | GR ACS, dried over molecular sieves from an oven overnight before use |
| Ammonium chloride | Aldrich | 213330-2.5kg | ACS Reagent |
| Diethyl ether | Millipore | EX0190-5 | GR ACS, collected from a solvent purification system before use |
| Magnesium sulfate | Aldrich | 793612-500g | Anhydrous, reagent grade |
| p-toluene sulfonic acid monohydrate | Fisher | A320-500 | ACS Certified |
| Sodium bicarbonate | Fisher | 5233-500 | ACS Certified |
| Sodium carbonate | Amresco | 0585-500g | |
| Ruthenium(III) chloride trihydrate | Pressure Chemical | 4750 | 40% Metal |
| Iridium(III) chloride hydrate | Pressure Chemical | 5730 | 53% Metal |
| Methanol | Avantor | 3016-22 | AR ACS, distilled from Mg before use |
| Pentane | J. T. Baker | T007-09 | >98%, dried with a solvent purification system before use |
| Chloroform-d | Aldrich | 151823-150G | 99.8 atom % D |
| Molecular sieves 4 Å | Aldrich | 208590-1KG | dried in an oven at 140 °C before use |
| Celite 545 | Acros | AC34967-0025 | dried in an oven at 140 °C before use |
| Name | Company | Catalog Number | Comments |
| Equipment | |||
| Schlenk line, with vacuum and inert gas manifolds | Custom | NA | Used in Preps 1-4 |
| Solvent transfer manifold | Chemglass | AF-0558-01 | Used in 2.2 |
| Airfree filter funnel | Chemglass | AF-0542-22 | Used in 3.1.3 |
| Glovebox | Vacuum Atmospheres | OMNI | Used in 3.2.2 |
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