19980-25-7

Upstream product

• 75-77-4 chloro-trimethyl-silane 
• 103-79-7 1-phenyl-acetone 
• 123-72-8 butyraldehyde 
• 4071-88-9 trimethylsilanyl-acetic acid ethyl ester 
• 114643-78-6 4-Benzyl-1-trimethylsilanyl-pyridinium; iodide 
• 98-86-2 acetophenone 
• 18107-18-1 diazomethyl-trimethyl-silane 

Downstream Products

• 1066-40-6 Trimethylsilanol 
• 25975-32-0 enol of phenyl acetone 

Relevant academic research and scientific papers

Highly stereoselective oxazaborolidinium ion catalyzed synthesis of (Z)-silyl enol ethers from alkyl aryl ketones and trimethylsilyldiazomethane

Highly stereoselective (Z)-silyl enol ethers were prepared from alkyl aryl ketones and trimethylsilyldiazomethane (TMSD) using an oxazaborolidinium ion catalyst. In addition, ring-expanded silyl enol ethers were successfully constructed from cyclic ketones. Their synthetic utilities were shown by sequential Mukaiyama aldol and [2 + 2]-cycloaddition reactions.

Catalytic enantioselective amination of silyl enol ethers using chiral dirhodium(II) carboxylates: Asymmetric formal synthesis of (-)-metazocine

(Chemical Equation Presented) Dirhodium(II) tetrakis[N- tetrafluorophthaloyl-(S)-tert-leucinate], Rh2(S-TFPTTL)4, is an exceptionally efficient catalyst for enantioselective aminations of silyl enol ethers derived from acyclic ketone

A new method for the preparation of silyl enol ethers from carbonyl compounds and (trimenthylsily)diazomethane in a regiospecific and highly stereoselective manner

The reaction of lithium (trimethylsilyl)diazomethane with aldehydes and ketones has been investigated, and it has been found that quenching at low temperature with MeOH followed by addition of Rh2(OAc)4 gave silyl enol ethers in high yields. Quenching with other electrophiles (e.g., deuterium, MeI) gave terminal and substituted silyl enol ethers with complete control over regio- and stereochemistry. The mechanism of this novel process has been mapped out through a combination of deuterium labeling, ReactIR, and isolation of reaction intermediates. Copyright

Regio- and stereoselective synthesis of silyl enol ethers using a new base electrogenerated from hexamethyldisilazane

The hexamethyldisilazane magnesium salt, a new base readily electrogenerated in an undivided cell fitted with a sacrificial magnesium anode, using a normally equilibrating medium (DME/15% vol HMPA mixture), exhibited a surprising regioselectivity leading to the less highly substituted silyl enol ethers from unsymmetrical ketones. This regioselectivity was not temperature dependent, but was strongly dependent on the nature and proportions of the solvent/cosolvent mixture. Moreover, the reaction was different in pure NMP, and exclusively afforded, from 2-pentanone, the new silylated aldol (56% yield) which resulted from the condensation of the less highly substituted enolate with the ketone.

α-nitration of ketones via enol silyl ethers. Radical cations as reactive intermediates in thermal and photochemical processes

Highly colored (red) solutions of various enol silyl ethers and tetranitromethane (TNM) are readily bleached to afford good yields of α-nitro ketones in the dark at room temperature or below. Spectral analysis show the red colors to be associated with the intermolecular 1:1 electron donor-acceptor (EDA) complexes between the enol silyl ether and TNM. The formation of similar vividly colored EDA complexes with other electron acceptors (such as chloranil, tetracyanobenzene, tetracyanoquinodimethane, etc.) readily establish enol silyl ethers to be excellent electron donors. The deliberate irradiation of the diagnostic (red) charge-transfer absorption bands of the EDA complexes of enol silyl ethers and TNM at -40 °C affords directly the same α-nitro ketones, under conditions in which the thermal reaction is too slow to compete. A common pathway is discussed in which the electron transfer from the enol silyl ether (ESE) to TNM results in the radical ion triad [ESE?+, NO2?, C(NO2)3-]. A subsequent fast homolytic coupling of the cation radical of the enol silyl ether with NO2? leads to the α-nitro ketones. The use of time-resolved spectroscopy and the disparate behavior of theisomeric enol silyl ethers of α- and β-tetralones as well as of 2-methylcyclohexanone strongly support cation radicals (ESE?+) as the critical intermediate in thermal and photoinduced electron-transfer as described in Schemes 1 and 2, respectively.

Stereoselective electrochemical synthesis of silyl enol ethers using a sacrificial magnesium anode

The 2-pyrrolidone magnesium salt electrogenerated in an undivided cell fitted with a sacrificial magnesium anode allowed the stereoselective synthesis of Z-silyl enol ethers upon deprotonation of enolizable ketones in the presence of a complexing agent. Keywords: Silyl enol ethers; Stereoselective synthesis; Electrogenerated bases; Sacrificial magnesium anode

Chemistry of oxaziridines. 14. Asymmetric oxidation of ketone enolates using enantiomerically pure (camphorylsulfonyl)oxaziridine

The reagent-controlled asymmetric oxidation of tri- and tetrasubstituted ketone enolate anions 4 and 8 by enantiomerically pure (camphorylsulfonyl)oxaziridine 2 has been investigated. The stereoselectivities for oxidation of trisubstituted enolates 4a-d are good to excellent, 60-95% ee, while those for tetrasubstituted enolates 4e and 8 are lower; i.e., 21-30% ee. Isolated chemical yields for both types of enolate anions are good to excellent. The sodium enolate anions of 4a-d, which could be oxidized at -78°C, gave both higher yields and stereoselectivities than the corresponding lithium or zinc enolates, which required warming to higher temperatures for complete oxidation. The presence of HMPA generally had a deleterious effect on the stereoinduction. However, for oxidation of (E)- and (Z)-4d the highest ee's were observed in the presence of this additive. Investigation of the stereoselective trends reveals that the enolate substitution pattern and the enolate solution structure are the most important stereocontrol elements. The role that the enolate geometry has in the stereoinduction is less clear although Z enolates seem to exhibit higher stereoselectivities than the E enolates. The results obtained in this study have been formulated into a mechanistic rational involving an SN2-type substitution of the enolate anion on oxaziridine 2 via an "open" transition state.

SILICA SUPPORTED TETRABUTYLAMMONIUM FLUORIDE AS A CATALYST FOR THE SILYLATION OF CARBONYL ABD HYDROXY COMPOUNDS WITH ETHYLTRIMETHYLSILYLACETATE

the use of silica supported tetrabutylammonium fluoride (TBAF-SiO2) as a non hygroscopic catalyst for silylating ketones and aldehydes with ethyltrimethylsilylacetate (ETSA) gives predominantly kinetic and Z silylenolethers at room temperature.TBAF-SiO2/ETSA is also useful in the silylation of alcohols.

REGIO AND STEREOSELECTIVE PREPARATION OF ENOLATES FROM KETONES BY MEANS OF SODIUM BIS(TRIMETHYLSILYL)-AZIDE

The deprotonation of some ketones by sodium bis(trimethylsilyl)-azide is regio and stereoselective.The results are different from those observed with LDA.

Syntheses with N-Trimethylsilylheteroarylium Salts: Reactions with Aldehydes, Ketones and Carboxylic Acids. Comparison of Reactivity with Analogous N-Acylheteroarylium Salts

N-Trimethylsilylheteroarylium salts 2 can be characterized as efficient silylating reagents for carbonyl compounds (5 or 8) and carbonic acids 11, their reactivity is comparable to that of N-acylheteroarylium salts 1.In some cases (depending on the nature of the substrates), their silylating power can be stronger than the acylating power of comparable salts 1.This will be demonstrated in the case of enolizable examples of 5 and 8.