Bis(trimethylsilyl)acetylene

Bis(trimethylsilyl)acetylene

Names
IUPAC name Bis(trimethylsilyl)acetylene
Other names BTMSA
Identifiers
CAS Number	14630-40-1 Y
3D model (Jmol)	Interactive image
ChemSpider	76286 N
ECHA InfoCard	100.035.141
PubChem CID	84564
InChI InChI=1S/C8H18Si2/c1-9(2,3)7-8-10(4,5)6/h1-6H3 N Key: ZDWYFWIBTZJGOR-UHFFFAOYSA-N N InChI=1/C8H18Si2/c1-9(2,3)7-8-10(4,5)6/h1-6H3 Key: ZDWYFWIBTZJGOR-UHFFFAOYAF
SMILES C(#C[Si](C)(C)C)[Si](C)(C)C
Properties
Chemical formula	C8H18Si2
Molar mass	170.40 g·mol−1
Appearance	Colorless to white Liquid
Density	0.791 g/cm3
Melting point	26 °C (79 °F; 299 K)
Boiling point	134.6 ± 8.0 °C
Solubility in water	0.031 g/L
Hazards
Main hazards	Flammable, Irritant
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
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:

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. 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.

BTMSA is also used in the total synthesis of epibatidine (and analogs), and also in the synthesis of iclaprim.