KF/Al~2O~3/PEG 4000(FAP)存在下氯仿的Michael加成反应

在KF/Al~2O~3/PEG4000(FAP)存在下,氯仿可与α,β-不饱和羰基化合物进行Michael加成反应,得到中等产率的三氯甲基化合物。     

Aqueous‐mediated Michael Addition of Active Methylene Compounds with Nitroalkenes

A simple, atom economical and highly efficient green protocol has been developed for the synthesis of Michael adducts of nitroalkenes and 2‐amino‐2‐chromene derivatives by Michael addition of active methylene compounds (such as malononitrile and ethyl cyanoacetate) to nitroalkenes under aqueous‐mediated conditions. This green approach provided the desired products in high yields and the reaction scope proved to be quite broad.     

KF-Al_2O_3催化下达米酮与查尔酮的麦克尔加成反应

5，5-二甲基-1，3-环己二酮（达米酮）、1，3-二芳基-2-丙烯-1-酮（查尔酮 ）在KF-Al_2O_3催化下，在DMF中进行麦克尔加成反应，生成产物为1，3-二芳基- 3-（5，5-二甲基-3-羟基-2-环己烯-1-酮-2-基）-1-丙酮，产率良好。     

KF负载制备固体强碱的研究

本文探讨了KF/Al2O3具有高碱性的原因。KF预吸附痕量H2O后具有碱性且能化学吸附CO2, 但这些部分水合状态的F^-的碱性太弱, 还不能催化丁烯异构化反应。IR和TPDE结果证实KF/Al2O3在丁烯异构化反应中的主要活性位具有[Al-OH...F^-]物种。这些强碱位可在高温脱羟而被破坏, 导致KF/Al2O3的失活。KF被首次报道负载在AlPO4-5上产生强碱位并能催化丁烯异构化反应。     

KF-Al2O3催化下3-芳基-3-(5，5-二甲基-3-羟基-2-环己烯-1-酮-2-基)丙酰胺衍生物的合成

芳醛、5，5—二甲基—1，3—环己二酮、丙二酸亚异丙酯、芳胺在KF-Al2O3催 化下，在DMF中反应生成3—芳基—3—(5，5—二甲基—3—羟基—2—环己烯—1— 酮—2—基)丙酰胺衍生物，产率良好。     

Improved heteroatom nucleophilic addition to electron-poor alkenes promoted by CeCl3.7H2O/NaI system supported on alumina in solvent-free conditions

Conjugate addition of heteroatom nucleophiles to carbon-carbon double bonds conjugated with a strong electron-withdrawing group is one of the most important new bond-forming strategies in synthetic organic chemistry. Among the methods for these Michael additions, Lewis acids have shown the best promoter activity, and in particular, the use of reagents impregnated over inorganic supports is rapidly increased. With the increase of environmental consciousness in chemical research, the solvent-free Michael addition has attracted our attention. In continuation of our ongoing program to develop synthetic protocols utilizing cerium trichloride, we report an extension of the CeCl(3).7H(2)O/NaI combination supported under solvent-free conditions to promote heteroatom Michael addition. Using neutral alumina (Al(2)O(3)) as solid support permits us to circumvent some of the problems associated with the procedure where the inorganic support is silica gel. The CeCl(3).7H(2)O/NaI/Al(2)O(3) system works well for hetero-Michael additions utilizing weakly nucleophiles such as imidazoles and carbamates, and also the reaction proceeds with good yields in the case of Michael acceptors different from alpha,beta-unsaturated carbonyl compounds. An important synthetic application of this our methodology is the intramolecular aza-Michael reaction in producing 4-piperidinone derivatives, which are of interest as synthetic intermediates toward important classes of heterocycles.     

Reaction of [60]fullerene with free radicals generated from active methylene compounds by manganese(III) acetate dihydrate

The reaction of [60]fullerene with dimethyl malonate and diethyl malonate in the presence of manganese(III) acetate dihydrate (Mn(OAc)3.2H2O) for 20 min afforded singly bonded [60]fullerene dimers 1a and 1b in a 1,4-addition pattern. When the reaction time was extended to 1 h, 1,4-bisadducts 2a and 2b were obtained. Unsymmetrical 1,4-adduct 5 and C2 symmetrical 1,16-bisadduct 6 were obtained when diethyl bromomalonate was used as the active methylene compound. Reaction of [60]fullerene with malononitrile and ethyl cyanoacetate with the aid of Mn(OAc)3.2H2O produced methanofullerenes 7 and 8. It is proposed that all these products were formed the addition of free radicals from the active methylene compounds generated by Mn(OAc)3.2H2O.     

Reaction of 3-Methyleneisocamphanone with Derivatives of Malonic Acid

Reaction of 3-methyleneisocamphanone with malononitrile, ethyl cyanoacetate or diethyl malonate in the presence of catalytic quantities of alkali or under catalysis with tetramethylguanidine in ethanol proceeds according to classical scheme of the Michael reaction and gives rise to 3-exo-(2,2-dicyanoethyl)-, 3-exo-(2-cyano-2-ethoxycarbonylethyl)-, or 3-exo-(2,2-diethoxycarbonylethyl)isocamphanone respectively. When the reaction with ethyl cyanoacetate and diethyl malonate is carried out in methanol occurs transalkylation of the ester groups resulting in the corresponding methyl esters, and in THF occurs hydrolysis to form carboxylic acids. In ethanol or methanol in the presence of equimolar or excess amounts of alkali compounds with cyano groups suffer cyclization into the corresponding 2-alkoxy-3-cyano- or 1-alkoxy-3-alkoxycarbonyl-7,7,8-trimethylbicyclo[2.2.1]hepteno[2.3-b]pyridines. In THF partially form analogous tricyclic 2-hydroxypyridines.     

KF/Al2O3催化合成2-甲基-3-(3,4-亚甲二氧基苯基)丙烯醛

缩合;催化剂;洋茉莉醛;KF/Al2O3催化合成2-甲基-3-(3;4-亚甲二氧基苯基)丙烯醛     

Microwave Assisted Michael Addition of Cycloalkenones and Substituted Enones on the Surface of Alumina in Dry Media

The Michael addition of ethyl acetoacetate, acetyl acetone and ethyl cyanoacetate to cycloalkenones and β -substituted enones and enal has been accomplished efficiently on the surface of alumina under microwave irradiation in dry media.     

The reactivity of quaternary ammonium- versus potassium-fluorides supported on metal oxides: paving the way to an instantaneous detoxification of chemical warfare agents

The reactions of the chemical warfare agents (CWAs) 2,2'-dichloroethyl sulfide (HD), O-ethyl S-2-(diisopropylamino)-ethyl methylphosphonothioate (VX) and isopropyl methylphosphonofluoridate (GB) with various metal oxide-supported quaternary ammonium fluorides (QAF) and/or potassium fluoride (KF) reagents are described. These active sorbents, which were prepared by a modified procedure, include alumina, silica and titania, enriched with "available" (not bound to the surface) fluoride ions. Alumina-based fluoride reagents were found to be more active than their silica or titania counterparts. QAF/Al(2)O(3) reagents, compared to KF/Al(2)O(3), exhibit an exceptional reactivity toward HD, as demonstrated both in reaction rates and product identity. For example, with TBAF, t(1/2) is 15 min for the formation of the elimination product divinyl sulfide (DVS), while with KF, t(1/2) is 10 h for the formation of the hydrolysis product thiodiglycol (TDG). On the other hand, both sorbents reacted similarly against the nerve agents GB or VX. In order to increase the "available" fluoride content on the solid surface, the mixed active sorbent TBAF/KF/Al(2)O(3) (20/20/60) was developed. On this powder, all three CWAs were degraded instantaneously at the low loading of 1 wt% (t(1/2) < 2 min) and rapidly at the higher loadings of 5-10 wt% (t(1/2) of minutes scale). We assume that the relatively large amount of inorganic fluoride (KF) acts synergistically as a reservoir for the more reactive organic fluorides (TBAF). Moreover, the alumina surface hydroxyl groups may also operate as a water reservoir for the hydrolysis of VX or GB. Therefore, TBAF/KF/Al(2)O(3) might be considered as a promising destructive sorbent for CWAs.     

KF－Al2O3催化下3，4－二氢－2H－吡喃[3,2-h]喹啉衍生物的合成

芳醛、8－羟基喹啉与丙二腈或氰乙酸乙酯KF－Al2O3催化下反应生成一系列新 的3，4－二氢－2H－吡喃[3,2-h]喹淋衍生物，产物的结构通过单晶X射线确证。     

KF-Al~2O~3试剂在有机合成反应中的应用进展

综述了自1979年Yamawaki和Ando发现KF-Al~2O~3试剂的催化特性以来在有机合成反应中的应用研究进展。     

Tandem three-component reactions of aldehyde, alkyl acrylate, and dialkylmalonate catalyzed by ethyl diphenylphosphine

A new highly efficient three-component reaction of alkyl acrylate, aldehyde and dialkyl malonate using ethyl diphenylphosphine as organocatalyst has been described. Various highly functional compounds bearing hydroxyl groups and the ester functions can be easily prepared in moderate to good yields according to our one-step procedure. The reactions are believed to proceed via Morita-Baylis-Hillman reactions of alkyl acrylate and aldehydes, followed by the Michael addition reactions of dialkyl malonates. Our reactions indicated that the intermediate species formed in the phosphine-catalyzed MBH reaction are an effective organic base to catalyze the Michael addition reactions of dialkyl malonates to the preformed MBH adducts.     

The reaction of 2-arylsulfonyloxytropones and active methylene compounds The formation of 8-hydroxy-2H-cyclohepta[b]furan-2-one and 2-amino-8H-cyclohepta[b]furan-8-one derivatives

Reaction of 2-arylsulfonyloxytropones (IV) and active methylene compounds, diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, malononitrile or cyanoacetamide, in the presence of NaOEt give 8-hydroxy-2H-cyclohepta[b]furan-2-one derivatives (V) and/or 2-amino-8H-cyclohepta[b]furan-8-one derivatives (VII), in addition to azulene derivatives (1) or 2H-cyclohepta(b]furan-2-one derivatives (II), known to be obtained by the reaction of 2-chlorotropones or 2-methoxytropones with active methylene compounds. Relative yields of products are influenced markedly by conditions, e.g. base type or molar ratios. The formation of V and VII is characteristic of 2-arylsulfonyloxytropones, not being observed with 2-chlorotropones or 2-methoxytropones. A reaction course involving elimination of the arylsulfonyl group as arenesulfinate ion is presented.     

3-芳基-3-环己烯基丙酸酯衍生物的合成和晶体结构

在KF-Al~2O~3催化下,将芳香醛、5,5-二甲基-1,3-环己二酮及丙二酸亚异丙酯在醇中反应,一锅式合成了一系列的3-芳基-3-(5,5-二甲基-3-羟基-2-环己烯-1-酮-2-基)丙酸酯。通过单晶X射线衍射分析确定了产物的结构,并提出了可能的反应机理。     

Reactions of CH-acids with α,β-unsaturated aldehydes in ionic liquids

Metal carbonate-catalyzed reactions of CH-acids (diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and ethyl 2-acetyl- and 2-ethoxycarbonyl-5,9-dimethyldeca-4,8-dienoates) with ,-unsaturated aldehydes (acrolein, crotonaldehyde, citral) were studied in an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF₆], and in a 1-butyl-3-methylimidazolium bromide ([bmim][Br]) — benzene system. The reactions with acrolein and crotonaldehyde afforded Michael addition products, those with citral resulted in Knoevenagel addition products. Sonication increased the yields of the Michael adducts. The ionic liquid [bmim][PF₆] can be recovered and repeatedly used in the reactions.     

Reactions of styryl and phenylethynyl sulfones with some CH-acids

Reactions of methyl and p-tolyl phenylethynyl sulfones with enolated of dimethyl malonate and malononitrile lead to the formation of sulfonyl-substituted derivatives of ethylidenemalonic acid. Methyl (E)-β-styryl sulfone reacts with sodium enolates of dimethyl malonate, malononitrile, and methyl cyanoacetate to give common Michael adducts.     

A Lewis acid-promoted cyclization of ethenetricarboxylate derivative aromatic compounds. Novel syntheses of oxindoles and benzofuranones via Friedel-Crafts intramolecular Michael addition

A novel cyclization reaction of ethenetricarboxylate derivative aromatic compounds in the presence of various Lewis acids gave benzo-annulated cyclic compounds such as oxindole and benzofuran derivatives via Friedel-Crafts intramolecular Michael addition in high yields. For example, the reaction of diethyl 2-[(N-methyl-N-phenylcarbamoyl)methylene]malonate (1a) in the presence of ZnCl2 at room temperature gave diethyl 2-(1-methyl-2-oxoindolin-3-yl)malonate (2a) in 98% yield. The reactions also proceeded with a catalytic amount of a Lewis acid such as AlCl3, ZnCl2, ZnBr2, Sc(OTf)3, or InBr3.     

TiO2 Nanopowder Catalyzed Microwave-Induced One-Pot Synthesis of Novel Quinoline/Benzo[h]quinoline3-carbonitrile Under Solvent Free Conditions

A rapid and efficient method for the synthesis of various carbonitrile quinoline/benzo[h]quinolines has been developed through the Knoevenagel condensation, Michael addition of aromatic aldehyde/amine with carbonyl compounds in the presence of a nanostructured TiO₂ photocatalyst by microwave irradiation under solvent-free conditions.