| Bis(trimethylsilyl)acetylene | |
|---|---|
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Bis(trimethylsilyl)acetylene |
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Other names
BTMSA |
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| Identifiers | |
| CAS number | 14630-40-1 |
| Properties | |
| Molecular formula | C8 H18 Si2 |
| Molar mass | 170.40192 |
| Appearance | Colorless to white Liquid |
| Density | 0.791 g/cm3 |
| Melting point |
26°C |
| Boiling point |
134.6 ± 8.0°C |
| Solubility in water | 0.031 g/L |
| Hazards | |
| Main hazards | Flammable, Irritant |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Bis(trimethylsilyl)acetylene (BTMSA) is an organosilicon compound with the formula C2(Si(CH3)3)2. It is a colorless liquid that is soluble in organic solvents. This compound is used as a surrogate for acetylene.
BTMSA is prepared by treating acetylene with butyl lithium followed by addition of chlorotrimethylsilane:[1][2]
BTMSA is used as a nucleophile in Friedel-Crafts type acylations and alkylations and a precursor to lithium trimethylsilylacetylide. The TMS groups can be removed with tetra-n-butylammonium fluoride (TBAF) and replaced with protons. BTMSA is also a useful reagent in cycloaddition reactions. Illustrating its versatility, BTMSA was used in a concise total synthesis of (±)-estrone.[3] A key step in this synthesis was the formation of the steroidal skeleton, catalyzed by CpCo(CO)2:
BTMSA also serves as a ligand in organometallic chemistry. For example, it forms stable adducts with metallocenes.[4]