Study of induced hypohalogenation of 1-alkyl(4-methylcyclohex-1-enyl)alkanones,and chemical transformations of the obtained compounds

Induced hydroxyhalogenation of alkyl cyclohexenyl ketones in the systems [MHlg-HX or HHlg]-H₂O₂ or (NaClO) was performed and the optimal conditions of this reaction were elucidated. It is established that in the system in situ is induced a hypohaloid acid HClO or HBrO is produced that then enters into electrophilic addition at the ring double bond affording hydroxyhalo derivatives of the cycloaliphatic ketones. The alkyl cyclohexenyl ketone chloro(bromo)hydrines and the oxiranes obtained from them are very reactive compounds and can be used as initial compounds for the synthesis of many individual organic compounds     

Liquid-phase synthesis of cyclic diene diepoxides using metal halides and hydrogen peroxide

Optimal conditions were found for induced hydroxyhalogenation of cyclic dienes (tetrahydroindene, 4-vinylcyclohexene and 5-vinyl- and 5-cyclohexenylbicyclo[2.2.1]hept-2-enes) in the system [MHlg-HA or HHlg]-H₂O₂ (or NaClO). Dehydrohalogenation of the chloro- and bromohydrins thus obtained with powdered potassium carbonate gave the corresponding diepoxy derivatives, and their hydrolysis led to mixtures of stereoisomeric tetrahydric alcohols.     

Dipiiosphoniomethanes with Hydrogen Atom,OH- And SH-Groups at Phosphorus

Abstract

Recently it has been shown that the interaction of equimolar amount of HHlg witii phosphinosubstituted ylides (I) and phosphoryl- and thiophosphorylsubstituted ylides (II) leads to monoprotonation products: at the carbon or phosphorus of (I) and at the carbon or oxygen (sulfur) of (II)¹. We have found that products of double protonation, diphosphoniomethanes with P-H (III) and P-OH (IV) bonds respectively, are formed by the action of excess acid (HSO₃F, HHlg).     

Cs2.5H0.5PW12O40 catalyzed diastereoselective synthesis of β-amino ketones via three component Mannich-type reaction in water

A series of insoluble salts of Keggin heteropoly compounds were prepared and used as catalysts for the Mannich-type reaction of benzaldehyde, aniline, and cyclohexanone in water. Among them, Cs_2.5H_0.5PW₁₂O₄₀ showed excellent catalytic activity. Effects of surfactant, catalyst loading and temperature were studied to introduce the best reaction condition. The optimized reaction conditions were extended to Mannich reaction of various aldehydes, ketones, and amines in water. This rapid procedure afforded structurally divers β-amino ketones with major anti diastereoselectivity. Additionally, four new compounds were reported. The catalyst was recovered and reused for subsequent runs.     

Generation of alkyl hypochlorites in oxidation of alcohols with carbon tetrachloride catalyzed by vanadium and manganese compounds

Primary alcohols and diols with various structures were subjected to transformations into esters, aldehydes, ketones, and lactones under the action of carbon tetrachloride in the presence of manganese compounds (MnCl₂, MnO₂, Mn(OAc)₂, Mn(acac)₃) and vanadium compounds (VCl₅, V₂O₅, VO(acac)₂) as catalysts. These transformation proceeded with the involvement of alkyl hypochlorites, which were generated in the course of oxidation of alcohols with carbon tetrachloride catalyzed by manganese or vanadium compounds. The optimum molar ratios between the catalyst and reagents were determined, and the reaction conditions for the highly selective synthesis of esters, aldehydes, ketones, and lactones from alcohols were found.     

Action du phenyltetrafluorophosphorane sur les α ou β hydroxy-esters, -cetones, -Nitriles, -ethers,et les nitroalcools. Acces a quelques derives fonctionnels α ou β fluores

The reaction of phenyltetrafluorophosphorane with secondary or tertiary α- or β -hydroxy esters, ketones, nitriles, ethers and nitro derivatives has been investigated. The formation of the alkoxyfluorophosphorane 3 has been established in several cases. Good yields of isolated fluoro compounds were obtained with MeCHFCOOEt, MeCHFCH₂COOEt and Me₂CFCH₂NO₂. These compounds eliminate HF readily.     

Facile synthesis of α,β-acetylenic ketones and 2,5-disubstituted furans: consecutive activation of triple and double bond with ZnBr2 toward the synthesis of furan ring

α,β-Acetylenic ketones were synthesized from the reaction of acid chlorides and acetylenic compounds in the presence of ZnBr₂ and DIEA in acetonitrile. From the acetylenic ketones having nearby methylene unit, 2,5-disubstituted furan derivatives could be synthesized under the same reaction conditions.     

A novel deacylation during the amination of trifluoromethyl β-dicarbonyl compounds

Starting from trifluoromethyl β-dicarbonyl compounds, a rare loss of CF₃CO was observed in the amination reactions performed under heterogeneous conditions using NsONHCO₂Et as the aminating agent and CaO or NaH as the base, while corresponding nonfluorinated β-dicarbonyl compounds under analogous conditions give non deacylated aminated compounds. This reaction can facilitate a direct synthesis of N-substituted α-amino esters or α-amino ketones.     

Zirconium borohydride piperazine complex, an efficient, air and thermally stable reducing agent

A zirconium borohydride piperazine complex (Ppyz)Zr(BH₄)₂Cl₂, obtained by the reaction of an ethereal solution of ZrCl₄ and LiBH₄ with piperazine is a stable, selective and efficient reducing agent. (Ppyz)Zr(BH₄)₂Cl₂ reduces aldehydes, ketones, silylethers, α,β-unsaturated carbonyl compounds and esters. The reactions were performed in diethyl ether at room temperature or under reflux, and the yields of the corresponding alcohols were excellent. The selective reduction of aldehydes in the presence of ketones and complete regioselectivity in the reduction of α,β-unsaturated carbonyl groups were observed.     

Lactam acetals and acid amides. 31. Synthesis,protonation, and basicities of some heterocyclic enamino ketones

The protonation of cyclic enamino ketones of the pyrrolidine, piperidine, and hexahydroazepine series, as well as their noncyclic analogs, was studied by PMR spectroscopy. It is shown that the presence of a CH₂ or CH₃ group in the “enamine” position leads to C protonation (in CF₃COOH). In the case of enamino ketones that do not contain substituents in the “enamine” α position N-and O-protonated forms are observed in CF₃COOH. The measured pK_a values (in 10% alcohol) and the ΔpK_a values (in nitromethane) of the enamino ketones show that the compounds for which C protonation is characteristic are two to three orders of magnitude more basic than in the case of compounds that do not contain substituents in the “enamine” α position; this is explained by the different character of protonation. See [1] for communication 30. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 344–348, March, 1980     

Ring‐Shaped Phosphinoamido‐Magnesium‐Hydride Complexes: Syntheses,Structures, Reactivity,and Catalysis

A series of magnesium(II) complexes bearing the sterically demanding phosphinoamide ligand, L^?=Ph₂PNDip^?, Dip=2,6‐diisopropylphenyl, including heteroleptic magnesium alkyl and hydride complexes are described. The ligand geometry enforces various novel ring and cluster geometries for the heteroleptic compounds. We have studied the stoichiometric reactivity of [(LMgH)₄] towards unsaturated substrates, and investigated catalytic hydroborations and hydrosilylations of ketones and pyridines. We found that hydroborations of two ketones with pinacolborane using various Mg precatalysts is very rapid at room temperature with very low catalyst loadings, and ketone hydrosilylation using phenylsilane is rapid at 70 °C. Our studies point to an insertion/σ‐bond metathesis catalytic cycle of an in situ formed “MgH₂” active species.     

MoO2Cl2 as a novel catalyst for Friedel-Crafts acylation and sulfonylation

The use of MoO₂Cl₂ as a novel catalyst for Friedel-Crafts acylation and sulfonylation is described. A series of aromatic ketones and sulfones were prepared in moderate to good yields using acyl chloride or sulfonyl chloride in the presence of MoO₂Cl₂ (20 mol %), under solvent-free conditions.     

Novel Route to 4‐(Adamantan‐1‐yl)quinoline Derivatives Based on the Friedländer Condensation

2,3,4‐Trisubstituted quinolines, substituted with adamantan‐1‐yl or (adamantan‐1‐yl)methyl in the 4‐position, were prepared from the corresponding admantan‐1‐yl 2‐aminophenyl ketones or admantan‐1‐ylmethyl 2‐aminophenyl ketones and ketones with an α‐CH₂ group. These reactions were carried out under neat conditions or in toluene, and the products were obtained in moderate‐to‐excellent yields. The scope and limitations of the examined procedures are discussed. All new compounds are fully characterized by IR and NMR spectroscopy and mass spectrometry. The molecular structures of five new quinolines, obtained via single‐crystal X‐ray diffraction analyses, are discussed.     

Conversion of methyl ketones and methyl sulfones into α-deutero-α,α-difluoromethyl ketones and α-deutero-α,α-difluoromethyl sulfones in three synthetic steps

Deuterodifluoromethyl ketones and sulfones were assembled in three synthetic steps from methyl ketones and sulfones, respectively. The key synthetic transformation is the deuteration of the difluorocarbanion generated by the release of trifluoroacetate from highly α-fluorinated gem-diols. High levels of deuterium on the “CF₂D” group were routinely observed. This strategy is mild and versatile and it can be applied to both ketones and sulfones without additional concerns of over- or under-fluorination. Additional examples address issues of over-deuteration when compounds with other acidic protons are subjected to the reaction conditions. This process not only demonstrates a new method to install a “CF₂D” group but also extends the scope of trifluoroacetate release to sulfones.     

Oxidation of secondary alkanols with the system cerium ammonium nitrate—lithium bromide into ketones, α-bromo ketones,and α,α′-dibromo ketones

Oxidation of secondary alkanols with the system Ce(NH₄)₂(NO₃)₆—LiBr in aqueous acetonitrile gave ketones, α-bromo ketones, or α,α′-dibromo ketones. The selectivity of the reaction under standard conditions depends only on the molar ratio of the reagents (alkanol: Ce^IV: LiBr).     

Hydrosilylation and double silylation of carbonyl compounds with 1,1′-bis(dimethylsilyl)ferrocene using nickel- and platinum-catalysts

A series of ferrocene-based organosilicon compounds have been prepared via hydrosilylation or double silylation of carbonyl compounds with 1,1′-bis(dimethylsilyl)ferrocene using (C₂H₄)Pt(PPh₃)₂ or Ni(PEt₃)₄ catalysts. In general, while the platinum catalyst (C₂H₄)Pt(PPh₃)₂ preferentially produced cyclic double-silylated products, the Ni(PEt₃)₄ catalyst led to the hydrosilylated ferrocene products from aldehydes or ketones.     

Reactions of (E)-3,3,3-trichloro(trifluoro)-1-nitropropenes with enamines derived from cycloalkanones. A new type of ring-chain tautomerism in a series of cyclobutane derivatives and stereochemistry of the products

Depending on the reaction conditions, the reactions of (E)-3,3,3-trichloro-1-nitropropene with cyclohexanone enamines led to bicyclo[4.2.0]octanes or trisubstituted enamines, which are the ring-chain tautomers capable of reversible transformations. Diastereoselectivity of the reactions of (E)-3,3,3-trichloro(trifluoro)-1-nitropropenes with cycloalkanone enamines were studied, a series of hitherto unknown CX₃-containing nitroalkylated enamines and γ-nitro ketones were synthesized, the structures of novel compounds were determined by NMR spectroscopy and X-ray diffraction.     

Fluorohalogeno compounds. I. The grignard reaction of some fluorohalogenoethanes

An extension of the scope of the Grignard reaction of fluorinated compounds is reported. Fluorohalogenoethanes of the general formula CF₃CXYZ ( X = F,Cl,Br ; Y,Z = Cl,Br ) were found to undergo smoothly the metal-halogen exchange reaction with alkyl- or aryl-magnesium halides at low temperature to yield organometallic compounds CF₃CXYMgHal. The Grignard compounds were reacted with a series of aldehydes and ketones to give the corresponding alcohols in good to moderate preparative yields.     

One-Pot Synthesis of N-Substituted Alkylaminocyclohexanols by the Addition of Electrophiles Formed <Emphasis Type="Italic">in situ</Emphasis> in the System Н<Subscript>2</Subscript>О<Subscript>2</Subscript> + HBr (HCl)

Highly selective one-pot synthesis of N-substituted aminocyclohexanols has been performed by hydroxyhalogenation of the corresponding cyclohexenes with electrophilic reagents formed in situ in the system Н₂О₂ + HHlg (Hlg = Cl, Br), with subsequent substitution of halogen atoms with amines. Some products were tested as antimicrobial additives to motor oils and cooling lubricants and showed high antibacterial and antifungal activity.     

Synthesis of new iron–NHC complexes as catalysts for hydrosilylation reactions

A series of new piano‐stool iron(II) complexes comprising N‐heterocyclic carbene ligands [Fe(Cp)(CO)₂(NHC)]I (NHC = 1,3‐disubstituted imidazolidin‐2‐ylidene) have been synthesized and analyzed by ¹H NMR, ¹³C NMR, IR, elemental analysis and mass spectrometric techniques. These compounds were easily prepared from the reaction of disubstituted imidazolidin‐2‐ylidene with [FeI(Cp)(CO)₂] in toluene at room temperature. These complexes were tested in the catalytic hydrosilylation reaction of aldehydes and ketones with phenylsilane in solvent‐free conditions. After a basic hydrolysis step, the corresponding alcohols were obtained in good yields. Copyright © 2013 John Wiley & Sons, Ltd.