(Triisopropylsilyl)acetylene

Chemical Properties

clear colorless liquid

Physical properties

colorless clear liquid; bp 50–52 °C at 0.8 hPa (0.6 mmHg), flash point 56 °C (closed cup); d = 0.813.

Uses

(Triisopropylsilyl)acetylene (TIPS-acetylene) is an easily handled and inexpensive monoprotected acetylene used as an attractive substitute for trimethylsilylacetylene (TMSacetylene). The bulkier silyl protecting group of TIPS-acetylene provides stability in a wider range of reaction conditions than TMS-acetylene. Its higher boiling point also provides better handling and safety than TMS-acetylene (bp 87–88°C at 12 hPa (9 mmHg)). The general utility of TIPS-acetylene is often highlighted in the transition metal-catalyzed C–C bond formations， including but not limited to transition metal-catalyzed Coupling Reactions；Reaction of TIPS-acetylide with Electrophiles；Synthesis of Polyynes；Transition Metal-catalyzed Cross-addition of TIPSacetylene to Alkynes；Hydroalkynylation；Direct Alkynylation；Conjugate Addition；Cycloaddition；Ring-opening Reactions etc.

Uses

(Triisopropylsilyl)acetylene may be used as reagent for the rhodium-catalyzed asymmetric alkynylation of various α,β-unsaturated ketones. It may be used as reagent in the enantioselective synthesis of β-alkynylated nitroalkanes.

Application

(Triisopropylsilyl)acetylene is often used in palladium-catalyzed Sonogashira coupling reactions to react with aryl halides to generate terminal alkynes. This reaction has good functional group compatibility and is suitable for later modification of drug molecules. It can be used for rhodium-catalyzed asymmetric alkynylation of α,β-unsaturated ketones to generate products with high stereoselectivity.

General Description

Asymmetric addition of (triisopropylsilyl)acetylene to α,β,γ,δ-unsaturated carbonyl compounds in the presence of a cobalt/Duphos catalyst is reported. A Sonogashira coupling reaction between 1-bromo-3-iodo-5-tertbutylbenzene and (triisopropylsilyl)acetylene is reported.

Synthesis

Triisopropylsilylacetylene can be prepared by a one-step reaction of triisopropylsilyl bromide with acetylene gas.

storage

(Triisopropylsilyl)acetylene (Ethynyltriisopropylsilane) is stable to air and moisture, incompatible with strong acids, bases, or oxidants, and flammable vapor and liquid. Skin/eye contact and inhalation should be avoided.