Trimethylsilylketene Struktur

Trimethylsilylketene

Bezeichnung:Trimethylsilylketene

CAS-Nr4071-85-6

Englisch Name:Trimethylsilylketene

CBNumberCB1500224

SummenformelC5H10OSi

Molgewicht114.22

MOL-Datei4071-85-6.mol

Trimethylsilylketene physikalisch-chemischer Eigenschaften

Siedepunkt	80-82 °C(lit.)
Dichte	0.813 g/mL at 25 °C(lit.)
Brechungsindex	n20/D 1.413(lit.)
Flammpunkt	3 °F
Löslichkeit	Sol CH2Cl2, CHCl3, CCl4, THF, diethyl ether, and most standard organic solvents; reacts with alcoholic and amine solvents.
EPA chemische Informationen	Ethenone, (trimethylsilyl)- (4071-85-6)

Sicherheit

Kennzeichnung gefährlicher	F
R-Sätze:	11
S-Sätze:	7/9-16-29-33
RIDADR	UN 1993 3/PG 2
WGK Germany	3

Gefahreninformationscode (GHS)

Trimethylsilylketene Chemische Eigenschaften,Einsatz,Produktion Methoden

R-Sätze Betriebsanweisung:
R11:Leichtentzündlich.
Physikalische Eigenschaften
bp 81–82 °C; d 0.80 g cm?3.
Verwenden
Trimethylsilylketene is a reactive acylating agent for amines and alcohols; building block for synthesis of coumarins; synthesis of α-silyl ketones via the addition of organocerium reagents; treatment with stabilized ylides forms trimethylsilyl-substituted allenes;a cycloaddition with aldehydes affords β-lactones; forms small rings with diazomethane; treatment with n-BuLi forms a ketene enolate. It participates in the reactions of Trimethylsilylacetylation of Alcohols and Amines, Synthesis of Coumarins via Cyclization–Elimination, One-pot Formation of α-Silyl Ketones, Preparation of Trimethylsilyl-Substituted Allenes, Preparation of β-Lactones, Reaction with Diazomethane to Form Silylated Cyclopropanes and Cyclobutanones, Synthesis of Heterocycles, Formation of the Ketene Enolate, and other uses.
synthetische
Most often prepared (eq 1) by pyrolysis of ethoxy(trimethylsilyl)acetylene at 120??C (100 mmol scale, 65% yield).Recently, pyrolysis of t-butoxy(trimethylsilyl) acetylene has been shown to be a convenient alternative for the preparation of trimethylsilylketene (1). Thermal decomposition of t-butoxy(trimethylsilyl)acetylene causes elimination of 2-methylpropene slowly at temperatures as low as 50??C and instantaneously at 100¨C110??C (30 mmol scale, 63% yield). The main advantage of this method is that it is possible to generate trimethylsilylketene in the presence of nucleophiles, leading to in situ trimethylsilylacetylation (eq 2). Increased shielding of the triple bond prevents problems such as polymerization and nucleophilic attack that occur when the ketene is generated in situ from (trimethylsilyl)ethoxyacetylene. Trimethylsilylketene can also be prepared (eq 3) via the dehydration of commercially available trimethylsilylacetic acid with 1,3- dicyclohexylcarbodiimide (DCC) in the presence of a catalytic amount of triethylamine (100 mmol scale, 63%). Other typical methods used for ketene generation such as dehydrohalogenation of the acyl chloride and pyrolysis of the anhydride have been applied to the preparation of (1); however, both methods afford low yields.
There have been no significant developments in the methods used to prepare trimethylsilylketene (TMSK). However, Black et al. have published slight modifications. to the original preparation by Ruden, which primarily deals with accessing ethoxyacetylene.

Trimethylsilylketene Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

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