1-METHYL-1-(TRIMETHYLSILYL)ALLENE Property

Boiling point:

111-112 °C(lit.)

Density 

0.759 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.444(lit.)

Flash point:

19 °F

solubility 

sol CH2Cl2, benzene, THF, Et2O, and most organic solvents.

Safety

Hazard Codes 

F

Risk Statements 

11

Safety Statements 

16

RIDADR 

UN 1993 3/PG 2

WGK Germany 

3

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

Precautionary statements

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

1-METHYL-1-(TRIMETHYLSILYL)ALLENE Chemical Properties,Usage,Production

Physical properties

bp 111 °C; bp 54–56 °C/90 mmHg

Uses

It is widely used as propargylic anion equivalents; three-carbon synthons for [3 + 2] annulations leading to five-membered compounds including cyclopentenes,4 dihydrofurans, pyrrolines, isoxazoles, furans, and azulenes.

Uses

3-(Trimethylsilyl)-1,2-butadiene may be used for the synthesis of γ-(trimethylsilyl)allylborane.

Preparation

1-methyl-1-(trialkylsilyl)allenes can be conveniently prepared by the method of Vermeer. Silylsubstituted propargyl mesylates thus undergo SN2 displacement by the organocopper reagent generated from methylmagnesium chloride, copper(I) bromide, and lithium bromide 1-Methyl-1-(trimethylsilyl)allene is produced in 52% yield from commercially available (trimethylsilyl)propargyl alcohol in this fashion (eq 1). The t-butyldimethylsilyl and triisopropylsilyl analogs are synthesized by the same method in 90% and 58% yield, respectively. Propargyl alcohols bearing these and other trialkylsilyl groups can be prepared by treatment of propargyl alcohol with n-butyllithium and the appropriate trialkylsilyl chloride. Allenylsilanes bearing other C-1 substituents can be prepared in an analogous manner by using the appropriate Grignard reagents.