Trimethylsilyl ethyl Chloroformate

More recently, triphenyl[[2-(trimethylsilyl)ethoxy]methyl]-phosphonium chloride has found use in homologating a variety of architecturally complex aldehydes and ketones (eqs 4—7). Highlights include the chemoselective oleflnation of an aldehyde over a ketone (eq 5), the oleflnation of a sterically congested a-epoxy aldehyde (eq 6), and the homologation of a particularly challenging ketone by Overman and coworkers (eq 7).  

Christopher M. Adams Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA 

OH (6) Solubility insol H2O sol benzene, ether, THF, chloroform. Form Supplied in not commercially available. 

Preparative Method prepared from 2-(trimethylsilyl)ethanol and phosgene.  

Handling, Storage, and Precautions moisture sensitive stable for three months under nitrogen at 0 °C probably toxic handle in a fume hood. 

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ALCOHOLS Allyltrimethylsilane. (1,5-Cyclooctadiene)bis(methyldiphenylphos-phine)iridium hexafluorophosphate. Guaiacylmcthyl chloride. Lcvulinic acid. (3-( Primethylsilyljethoxymethyl chloride. 2-(Trimethylsilyl)ethyl chloroformate. Trimelhyllrityloxysilane. 

Trans-protection of A-benzyl piperidine is also possible using in situ generation of 2-(trimethylsilyl)ethyl chloroformate in the presence of a large excess of potassium carbonate. Upon completion of the synthetic sequence, deprotection was carried out using a fluoride source such as cesium fluoride in DMF at 90 °C (eq 30). ... 

Alternative reagents for the introduction of the Teoc group include 2-(trimethylsilyl)ethyl chloroformate (3 X = Cl), trimethylsilylethyl azidoformate (3 X = Ns), trimethylsilylethyl methoxyvinyl carbonate (4), trimethylsilylethyl 4-nitrophenyl carbonate (5), and the aminoxy carbonates (6). Of these, only the 4-nitrophenyl carbonate (5) is commercially available. The carbonate (5) has been used to block NH groups in amino acids and indoles. ... 

Protection of Amines. 2-(Trimethylsilyl)ethyl chloroformate (1) is a useful reagent for the introduction of the trimethylsilylethoxycarbonyl (Teoc) protecting group for amines. " For example, p-chloroaniline reacts with (1) to form the ex-(7) pected trimethylsilylethyl carbamate (eq 1). The Teoc protecting group is stable to hydrogenation (H2, palladium on carbon) and mild acid or base. It can be removed with fluoride ion or with a strong acid (e.g. trifluoroacetic acid). It is possible to selectively cleave a t-butyldimethylsilyl... 

Related Reagents. Allyl Chloroformate 4-Bromobenzyl Chloroformate f-Butyl Chloroformate Ethyl Chloroformate 9-Fluorenylmethyl Chloroformate Isobutyl Chloroformate Methyl Chloroformate 2,2,2-Tribromoethyl Chloroformate 2,2,2-Trichloroethyl Chloroformate 2,2,2-Trichloro-r-butoxycarbonyl Chloride 2-(Trimethylsilyl)ethyl Chloroformate Vinyl Chloroformate. 

Related Reagents. Allyl Chloroformate Benzyl Chlo-roformate 4-Bromobenzyl Chloroformate t-Butyl Azidoformate l-(t-Butoxycarbonyl)-lEf-benzotriazole 3-A-oxide 1 -(r-Butoxycarbonyl)imidazole 2-(t-Butoxycarbonyloxyimino)-2-phenylacetonitrile A-(t-Butoxycarbonyloxy)phthalimide A-(t-Butoxycarbonyloxy)succinimide V-(r-Butoxycarbonyl)-1,2,4-triazole Di-t-butyl Dicarbonate Ethyl Chloroformate 9-Fluorenylmethyl Chloroformate Isobutyl Chloroformate Methyl Chloroformate 2,2,2-Tribromoethyl Chloroformate 2,2,2-Trichloroethyl Chloroformate 2,2,2-Trichloro-t-butoxycarbonyl Chloride 2-(Trimethylsilyl)ethyl Chloroformate Vinyl Chloroformate. 

Related Reagents. 2-(Trimethylsilyl)ethoxycarbonylimidazole 2-(Trimethylsilyl)ethoxymethyl Chloride 2-(Trimethylsilyl)-ethyl Chloroformate. 

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