Trifluoromethylthiolation of Trimethylsilyl Enol Ethers

The treatment of bis-(1,2-trimethylsilyloxy)-1-cyclobutene, 1-(1-trimethylsilyloxy)cyclpentene and 1-(1-trimethylsilyloxy)cyclohexene with trifluoromethylsulfenyl chloride has been found to furnish trifluoromethylthiolated carbonyl derivatives.     

The Chemistry of Enol Ethers

Enol ethers (vinyl ethers) are intermediate in their reaction behavior between olefins and enamines. This article presents a survey of reactions leading to bond formation at the β? C atom of enol ethers; polymerizations and additions of acidic H? X compounds are not reviewed.     

BiX3 and FeX3‐Promoted Prins Cyclization of Enol Ethers in CH2Cl2

The Prins cyclization of enol ethers has been realized by employing BiX₃ (or FeX₃) as catalyst and TMSX (X=Br, Cl) as the halogen source. The presence of a tiny amount of water in the solvent dichloromethane played a key role for the reaction to proceed. The reaction is believed to be catalyzed by Lewis acid‐assisted Brønsted acids, which were generated in situ from MX₃ and water in the solvent.     

Synthesis of Silicon-Functionalized Dimethylsilyl Enol Ethers from Ketones

Symmetrical dimethylsilyl bis-enol ethers are obtained in good yield by reaction of ketones with dichlorodimethylsilane in the presence of triethylamine and sodium iodide. Reaction of ketones with N, N - diethylaminodimethylchlorosilane in the presence of triethylamine and sodium iodide followed by subsequent conversions provides a useful synthesis of silicon-functionalized dimethylsilyl enol ethers including unsymmetrical dimethylsilyl bis-enol ethers     

黄烷酮烯醇硅醚氧化重排成异黄酮

3,3″-偶联的双黄烷酮类化合物自1979年首次从瑞香狼毒中分离得到以来,对于它们的合成一直受到重视。我们试图应用Moriarty等人发现的用氧化碘苯氧化酮的烯醇硅醚合成1,4-二芳基-1,4-二酮的方法。     

Alkyl Enol Ethers: Development in Intermolecular Organic Transformation

Alkyl enol ethers (AEE) are versatile synthetic intermediates with a unique reactivity pattern. This review article summarizes the synthesis of AEE as well as its reactivity and how enol ether undergoes intermolecular reactions for various bond formation, leading to the construction of several useful organic molecules. The synthetic applications of alkyl enol ethers towards intermolecular bond-forming reactions include metal-catalyzed reactions, cycloaddition and heterocycle formation as well as rwactions in the field of natural products synthesis. The achievement of these impressive transformations prove the countless synthetic potential of AEE. The main objective of this review is to bring attentiveness among synthetic chemists to show how AEE extensively can be used to react with both electrophiles as well as nucleophiles, thereby behaving as an ambiphilic reactant. We trust that the unique reactivity pattern of alkyl enol ethers and the fundamental mechanistic idea can attract chemists in AEE chemistry. Exclusively, intermolecular reactions of AEE with other functionalized moieties have not been reviewed to the best of our knowledge.     

An Efficient Regio and Stereoselective Synthesis of Silyl Enol Ethers

Ketones and aldehydes on treatment with NaBr-Me₃SiCl-Et₃N in DMF at ambient temperature yield silyl enol ethers with high regio- and stereoselecti-vity.     

Synthesis and Cationic Polymerization of Open-Chain and Cyclic Enol Ethers

Abstract

Several new open-chain and cyclic enol ether monomers were prepared using simple, straightforward procedures. The reactivities of these monomers were compared using both differential scanning photocalorimetry and Fourier transform real-time infrared spectroscopy. In general, these new monomers were found to possess excellent reactivity in photoinitiated cationic polymerization using a diaryliodonium salt photoinitiator.     

FLP‐Catalyzed Transfer Hydrogenation of Silyl Enol Ethers

Herein we report the first catalytic transfer hydrogenation of silyl enol ethers. This metal free approach employs tris(pentafluorophenyl)borane and 2,2,6,6‐tetramethylpiperidine (TMP) as a commercially available FLP catalyst system and naturally occurring γ‐terpinene as a dihydrogen surrogate. A variety of silyl enol ethers undergo efficient hydrogenation, with the reduced products isolated in excellent yields (29 examples, 82 % average yield).     

Catalyst-Controlled Transannular Polyketide Cyclization Cascades: Selective Folding of Macrocyclic Polyketides

The biomimetic synthesis of aromatic polyketides from macrocyclic substrates by means of catalyst-controlled transannular cyclization cascades is described. The macrocyclic substrates, which feature increased stability and fewer conformational states, were thereby transformed into several distinct polyketide scaffolds. The catalyst-controlled transannular cyclizations selectively led to aromatic polyketides with a defined folding and oxygenation pattern, thus emulating β-keto-processing steps of polyketide biosynthesis.     

The Methyl Enol Ethers of Ethyl 2, 4-Dioxopentanoate

Methylation of ethyl 2, 4-dioxopentanoate with diazomethane gives a mixture of two enol ethers, the 2-methoxy and the 4-methoxy isomer, with a product ratio which depends upon reaction temperature. Both enol ethers, initially (Z)-configurated, isomerize to the corresponding (E)-conformers, the 4-methoxy compound with particular ease.     

Stereoselective Access to Fully Substituted Aldehyde-Derived Silyl Enol Ethers by Iridium-Catalyzed Alkene Isomerization

An in situ generated cationic Ir-catalyst isomerizes simple allylic silyl ethers into valuable, fully substituted aldehyde-derived silyl enol ethers. Importantly, by judicious choice of substrate, either of the two possible stereoisomers of a given enolate derivative is accessible with complete stereoselectivity. One-pot isomerization-aldol and isomerization-allylation processes illustrate the synthetic utility of this method.     

Cyclization of Olefinic Benzyl Ethers with Aryltellurium Trichlorides

Olefinic benzyl ethers react with aryltellurium trichlorides leading to tetrahydrofurans in high yields. The reaction times and yields are similar to the analogous cyclization of the corresponding olefinic alcohols. The stereoselec-tivity of the transformation is low.