(2-BROMOALLYL)TRIMETHYLSILANE Property

Boiling point:

82-85 °C/60 mmHg (lit.)

Density 

1.121 g/mL at 25 °C (lit.)

refractive index 

n20/D 1.462(lit.)

Flash point:

87 °F

storage temp. 

2-8°C

solubility 

sol alcohol, acetone, ether, THF, pentane; insol water.

BRN 

3600686

Safety

Hazard Codes 

Xi

Risk Statements 

10-36/37/38

Safety Statements 

16-26-36

RIDADR 

UN 1993 3/PG 3

WGK Germany 

3

F 

8-10

HS Code 

2931.90.9010

HazardClass 

3.2

PackingGroup 

III

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H226Flammable liquid and vapour

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

(2-BROMOALLYL)TRIMETHYLSILANE Chemical Properties,Usage,Production

Physical properties

bp 46–50°C/20 mmHg,64–65°C/38– 39 mmHg.

Uses

2-Bromo-3-trimethylsilyl-1-propene can be used as synthon for CH2=C?CH2TMS1–3 and CH2=CBrC?H2;2 for synthesis of 1-trimethylsilylmethyl-substituted 1,3-butadienes.
The 1-trimethylsilylmethylvinyl anion CH2=C(M)CH2TMS (2) (M = Li, Mg, Cu, etc.), readily prepared from 2-bromo-3-trimethylsilyl-1-propene (1) under typical conditions, allows the introduction of the synthetically useful 1-trimethylsilylmethylvinyl group to a wide variety of substrates. Ring opening of 1-butene oxide with the Grignard reagent (2) (M = MgBr) in the presence of copper(I) iodide gives only one regioisomer. Subsequent desilylative oxidation of this allyl alcohol to α-methylene-γ-lactones provides further utility of (1) as a 1-hydroxymethylvinyl anion equivalent, i.e. CH2=?C?CH2OH (eq 1).Alternatively, the alcohol from trans-2,3-epoxybutane provides a route to the unstable sixmembered β,γ-unsaturated lactone (eq 2).The copper-catalyzed 1,4-addition to the typically unreactive mesityl oxide proceeds smoothly. The versatility of the allylsilane moiety is again illustrated in the ethylaluminum dichloride-induced cyclization of the adduct to a tertiary cyclopentanol in high yield (eq 3).

Preparation

reaction of 2,3-dibromopropene with lithium (trimethylsilyl)cuprate in HMPA at 0°C (63–90%);(2) reaction of 2,3-dibromopropene with trichlorosilane in the presence of trichlorosilane and copper( I) chloride, followed by treatment with methylmagnesium bromide (63–71%).

Purification Methods

It is fractionally distilled through an efficient column. It is flammable. [Trost & Chan J Am Chem Soc 104 3733 1982, Trost & Coppola J Am Chem Soc 104 6879 1982.]