74209-79-3

Upstream product

• 6651-36-1 1-(Trimethylsilyloxy)cyclohexene 
• 77-76-9 2,2-dimethoxy-propane 
• 75697-54-0 (1-Methoxy-1-methyl-ethylsulfanyl)-benzene 

Downstream Products

• 128258-97-9 2-(2-isothiocyanatopropyl-2)-1-cyclohexanone 

Relevant academic research and scientific papers

Base-promoted ring expansion of 3-aminopyrimidine-2-thiones into 1,2,4-triazepine-3-thiones

A base-promoted ring expansion of 3-amino-4-hydroxyhexahydropyrimidine-2-thiones into 2,4,5,6-tetrahydro-3H-1,2,4-triazepine-3-thiones has been developed. Experimental data and DFT calculations showed that the reaction proceeded through fast formation of intermediate acyclic isomers of pyrimidines followed by their slow cyclization into triazepines. The starting hydroxypyrimidines were prepared by reaction of α,β-unsaturated ketones or β-alkoxy ketones with HNCS followed by treatment of the obtained β-isothiocyanato ketones with hydrazine. Triazepine-3-thiones were transformed into their 3-oxo analogs by oxidation with H2O2 under basic conditions.

Carbon-carbon bond forming reactions by using bistrifluoromethanesulfonimide

Bistrifluoromethanesulfonimide has been used to catalyze C-C bond forming reactions such as Friedel-Crafts, Mukaiyama, 1,2-addition and 1,4-addition as well as C-glycosidation reactions.

Lewis acid mediated selective chalcogenalkylation of silyl enol ethers with [O,S]-acetals

Silyl enol ethers of ketones were selectively alkylated with [O,S]- acetals mediated by Lewis acid in a Mukaiyama type Aldol reaction. The products were β-alkoxy- and/or β-sulfanyl carbonyl compounds depending on the catalyst employed.

Bismuth(III) Triflate: A Water-Stable Equivalent of Trimethylsilyl Triflate for the Catalysis of Mukaiyama Aldol Reactions

Bismuth tris-trifluoromethanesulfonate (1) has been found to be an efficient catalyst for the Mukaiyama aldol-type reactions.The catalytic activity of this catalyst is higher than the one previously reported for the rare earth triflates M(OTf)3 (M = Sc, L

Chemoselective aldol type condensation of silyl enol ethers and acetals in 5 mol dm-3 lithium perchlorate-diethyl ether

Acetals are efficiently and chemoselectively converted into the corresponding aldol ethers upon treatment with 1-trimethylsilyloxycyclohexene 2 in 5 mol dm-3 lithium perchlorate-diethyl ether (LPDE) at ambient temperature with moderate diastereoselectivity, whereas under the same conditions aldehydes and ketals fail to react with 2.The present method allows the acetal substitution to be carried out under neutral reaction and work up conditions.A mechanism involving the formation of an oxocarbenium ion intermediate from the acetal followed by nucleophilic addition of the silyl enol ether is proposed.The observed chemoselectivity is attributed to the mild Lewis acidity of the lithium ion in diethyl ether.

Trimethylsilyl bis(fluorosulfonyl)imide: A New Catalyst for the Reactions of Acetals with Silyl Nucleophiles

A new catalyst trimethylsilyl bis(fluorosulfonyl)imide has been prepared for aldol type reactions and allylation of acetals.The catalyst has been found to be more active than trimethylsilyl triflate for the above reactions. - Key words: Trimethylsilyl bis

TRIMETHYLSILYL TRIFLATE CATALYZED ALDOL-TYPE REACTION OF ENOL SILYL ETHERS AND ACETALS OR RELATED COMPOUNDS

Trimethylsilyl triflate with or without added hindered tertiary amines catalyzes directed condensation of enol trimethylsilyl ethers with acetals, orthoformate, or 2-acetoxytetrahydrofuran or -pyrans to give the corresponding β-alkoxy carbonyl compounds.R

Crossed aldol-type reactions catalyzed by rhodium complexes

Crossed aldol-type reactions of enol trimethylsilyl ethers with aldehydes and ketones are smooth when carried out with a catalytic amount of a rhodium complex, Rh4(CO)12 or X (X=PF6 and ClO4; COD=cycloocta-1,5-diene, DPPB=1,4-bis(diphenylphosphino)butane), under neutral conditions.A suitable catalyst enables the isolation of three different types of aldol reaction product, β-trimethylsiloxy ketones, β-hydroxy ketones, and α,β-unsaturated ketones.Rh4(CO)12 and ClO4 also catalyze the reaction of enol trimethylsilyl ethers with acetals or ketals, whereas PF6 does not.When ClO4 is used as the catalyst, this type of aldol reaction is extended to the one-pot synthesis of trisubstituted furans from enol trimethylsilyl ether and α-trimethylsiloxy acetal.

Electrogenerated Acid-Catalyzed Reactions of Acetals, Aldehydes, and Ketones with Organosilicon Compounds, Leading to Aldol Reactions, Allylations, Cyanations, and Hydride Additions

Exquisite use of electrogenerated acid (EG acid) in the silicon-mediated acid-catalyzed reactions; e.g., aldol reactions, allylations, cyanations, and hydride additions is described.The aldol reaction of acetals 1 with enol trimethylsilyl ethers 3 and 1,2-bis(trimethylsiloxy)alkenes 4 gives the corresponding adducts 5 and 6, respectively.The reaction proceeds smoothly with EG acid derived from perchlorate salts such as LiClO4, n-Bu4NClO4, and Mg(ClO4)2 in dichloromethane using platinum electrodes.The amount of electricity required to complete the reaction implies a cationic process which is mediated by the trimethylsilyl moiety.This aldol reaction is further developed with unprotected carbonyl compounds 2 with 3, giving the trimethylsilyl ethers of the adducts 7.Further utility of this EG acid as a catalyst for a chain reaction is exemplified by the successful application in the following conversions: (1) The allylation of acetals 1 with allyltrimethylsilane (8) to give 9, (2) the cyanation of acetals 1 and unmasked 2 with trimethylsilyl cyanide (10) to give 11, 12, and 13, and (3) the hydride addition of acetals 1 with triethylsilane (14) to give 15.

CHEMISTRY OF ENOL ETHERS. LXVIII. SILYL ENOL ETHERS IN A MODIFIED ALDOL-CROTONIC CONDENSATION. PRODUCTION OF α,β-UNSATURATED KETONES

By the condensation of the acetals of acetaldehyde, butyraldehyde, isobutyraldehyde, and acetone with the trimethylsilyl ethers of the enolic forms of cyclohexanone, cyclopentanone, and acetone in the presence of zinc chloride as catalyst and subsequent treatment of the reaction products with dilute hydrochloric acid the following α,β-unsaturated ketones were obtained: Ethylidene-, butylidene-, and isobutylidenecyclohexanones, the corresponding cyclopentanones, and methyl propenyl ketone.