Three-Component Spiro Heterocyclization of Pyrrolediones,Indane-1,3-dione,and Heterocyclic Enamines

Russian Journal of Organic Chemistry - 3-Methyl-2′,5-dioxo-5′-phenyl-1′,2′,5,10-tetrahydrospiro(indeno[1,2-b]isoxazolo[4,3-e]pyridine-4,3′-pyrroles) and...     

Unusual Reaction of Diazo Compounds with Enamines

Transition metal catalyzed decomposition of diazo compounds and consequent transformations constitute various synthetic useful reactions in the past decades. The catalytic addition of diazo compounds to olefins generally provides cyclopropanes in high yield. However the reaction of electron-rich enamines with diazo compounds gave variable results. Wenkert et al. reported the reaction of enamines with ethyl diazoacetae (EDA) in the presence of cuprous chloride or silver oxide unexpectedly gave…     

Synthesis of Novel N-carbohydrate-derived Heterocyclic Compounds by Nucleophilic Substitution Reaction of Carbohydrate Imidazole-1-sulfonates

The nucleophilic substitution reaction of carbohydrate imidazole-1-sulfonates with pyrrole and other nitrogen heterocyclic compounds is reported for the first time. Several novel N-carbohydrate-derived heterocyclic compounds have been prepared by this displacement reaction. The desired carbon-nitrogen bond formation proceeds under mild conditions to generate the coupling products in good yields with readily available and inexpensive reagents. This method is particularly suitable for carbohydrate imidazole-1-sulfonates of primary alcohols. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file.     

串联型氮杂-迈克尔加成/分子内亲核取代反应构建1,3-硅杂四氢吡啶环

开发了2-硅-1,3-碘代对甲苯磺酰胺试剂。该试剂在碳酸钾促进下,可与炔酯以及烷基、芳基和杂环取代的炔酮发生串联型氮杂-迈克尔加成/分子内亲核取代反应,以中等至优秀的收率(40%~90%)得到相应的1,3-硅杂四氢吡啶产物。通过该方法,合成了16个结构新颖的1,3-硅杂四氢吡啶,其结构经¹H NMR,¹³C NMR和HR-MS(ESI)表征。      

Reaction of salicyl phosphites with hexafluoroacetone imine

Benzo-1,3,2,dioxaphosphorin-4-ones react with hexafluoroacetone imine to form 2-R-2,5-dioxo-3,3-bis(trifluoromethyl)-6,7-benzo,1,4,2-oxozaphosphepanes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No, 12, pp. 3008–3010, December, 1996.     

Action of Nucleophilic Phosphorus Reagents on Heterocyclic cis-Disulfides

As a contribution to previous studies of the reaction of phosphorus nucleophiles with heterocyclic cis-disulfides,^1,2 the reactivity of trialkyl phosphites 2 toward 5-p-chlorophenyl-4-cyano-1,2-dithiol-3-thione 1a, 5-phenyl-1,2,4-dithiazol-3-thione 1b and its 3-carbonyl derivative 1c has now been investigated.     

Reaction of Some Heterocyclic Formamidines with Trimethylsilylethynyllithium

The reaction of a 2-[(dimethylamino)methyleneamino]pteridine, two 2-[(dimethylamino)methyleneamino]pyrimidines, and a 2-[(dimethylamino)methyleneamino]pyrido[2,3-d]pyrimidine with trimethylsilylethynylithium in the presence of benzyl chloroformate leads to the corresponding 2-[bis(trimethylsilylethynyl)methylamino]-substituted heterocycles. A series of such substrates was prepared and some of the factors which permit this transformation were delineated. An X-ray crystal structure was determined of one of the products - 2-[bis(trimethylsilylethynyl)methylamino]-5,6,7,8-tetrahydro-3-(2,2-dimethylpropanoyloxymethyl)quinazolin-4-one.     

Three-Component Spiro Heterocyclization of Pyrrolediones with Indan-1,3-dione and Acyclic Enamines

Ethyl 4,5-dioxo-2-phenyl-4,5-dihydro-1H-pynole-3-carboxylates reacted with indan-1,3-dione and 3-amino-1-phenylbut-2-en-1-one or 3-aminobut-2-enenitrile to give 3-benzoyl-2-methyl-2′,5-dioxo-5′-prienyl-1,1′,2′,5-tetrahydrospiro[indeno[1,2-b]pyridine-4,3′-pyrroles] and 2-methyl-2′,5-dioxo-5′-phenyl-1,1′,2′,5-tetrahydrospiro[indeno[1,2-b]pyridine-4,3′-pyrrole]-3-carbonitriles, respectively.

     

The 1,3-Dipolar Cycloadditions of Nitrile Oxides and Nitrile Imines to Alkyl Dicyanoacetates

The readily available alkyl dicyanoacetates 1 reacted with the 1,3-dipolar reagents arenecarbonitrile oxides 2 ′ and arenecarbonitrile imines 5 ′ to afford 1,2,4-oxadiazol and 1,2,4-triazol derivatives. The arenecarbonitrile oxides 2 ′ with electron-donating groups on the arene ring gave products 3a – d resulting from addition on both CN groups of 1 , and those with electron-withdrawing groups provided mono-adducts 4a – e (Scheme 1). Arylnitrile imines 5 ′ reacted with 1 to offer both bis- and mono-addition products (Scheme 2); the bis-adducts 8a , b possess an ester structure, whereas the mono-adducts 6a – d present a ketene-hemiacetal structure.     

Heterocyclic Derivatives of Fullerene C60. 1. Synthesis of New Fulleropyrazolines by the 1,3-Dipolar Cycloaddition of Nitrile Imines

New stable [6,6]-closed cycloadducts, fulleropyrazolines containing aryl, hetaryl, trifluoromethyl, and other substituents in the five-membered ring, have been obtained by the 1,3-dipolar cycloaddition of nitrile imines to C₆₀. Two methods of generating nitrile imines in situ have been used, the dehydrohalogenation of the corresponding hydrazonoyl halides by the action of triethylamine and the thermal decomposition of 2,5-diaryltetrazoles.     

Reaction of Thioxanthylium Cation with Pharmacophoric Heterocyclic Amines

Russian Journal of Organic Chemistry - Reactions of thioxanthylium tetrafluoroborate with pharmacophoric heterocyclic amines, pyrimidin-2-amine, 4,6-dimethylpyrimidin-2-amine,...     

Diastereoselective silver-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with fluorinated imine

We described hereby an instance of diastereoselective silver-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with imine compounds. This new method provided synthetically useful, highly substituted tetrahydroimidazole derivatives with efficiency and high diastereoselectivity. We can conveniently obtain fluorinated dihydroimidazole, imidazole, and diamino esters through simple modification.     

Reaction of N‐Nonaflyl and N‐Cyano‐Benzotriazoles with Enamines

N‐Nonaflyl‐benzotriazole 1a reacts with enamines 2 in tetrahydrofurane (THF) at room temperature to afford o‐nonafluorobutansulfonamido‐phenylazo‐enamines 3 in 74–81% yield. Compound 1a reacts with 1‐diethylaminobutadien 2f twice, affording pyridazine derivative 3f in 20% yield. Ringopening of N‐cyano‐benzotriazole 1b with pyrrolidinocyclohexene 2a affords, under cleavage of pyrrolidine 1,2,3,4‐tetrahydro‐dibenzo[4,5:e]imidazo[1,2‐b][1,2,4]triazine 4 in 43% yield.