Synthesis of 2-(dibenzosuberen-5-yl)-1,3-dicarbonyl compounds

Reaction of dibenzosuberen-5-ol with 1,3-dicarbonyl compounds catalyzed with scandium(III), copper(II), or indium(III) triflate (5 mol %) afforded 2-(dibenzosuberen-5-yl)-1,3-dicarbonyl compounds in 63–86% yield.     

Synthesis of (1,3-adamantylene)bis-1,3-dicarbonyl compounds

Reactions of 1,3-dihydroxyadamantane with 1,3-dicarbonyl compounds in the presence of 5 mol % of In(OTf)₃ afforded a series of (1,3-adamantylene)bis-1,3-dicarbonyl compounds in yields of 25–83%.     

Synthesis and reactions of (E)- and (Z)-1,3-dibromo-2-methoxypropene

(Z)-1,3-Dibromo-2-methoxypropene is prepared in 90% yield by dehydrohalogenation of 1,2,3-tribromo-2-methoxypropane with diisopropylamine in dichloromethane. The E-isomer can be obtained as the only product in almost quantitative yield by UV irradiation of the Z-isomer. Nucleophilic displacement reactions of the allylic bromide and palladium-catalyzed coupling reactions of the vinylic bromide in (E)- and (Z)-1,3-dibromo-2-methoxypropene have been studied.     

Synthesis and reactivity of 2-(porphyrin-2-yl)-1,3-dicarbonyl compounds

A simple and efficient procedure for the synthesis of porphyrins bearing 1,3-dicarbonyl moieties at the β-position is described. The new compounds were further functionalized and new derivatives containing an heterocyclic ring, an ethyl acetate residue or a 2-oxopropyl group at the β-position have been obtained.     

Facile Stereoselective Synthesis of (E)-1-Arylseleno-Substituted 1,3-Enynes and Their Applications in Synthesis of (E)-Enediynes

(E)-1-Iodo-2-arylselenoethylenes 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 to afford (E)-1-arylseleno-substituted 1,3-enynes 3 in high yields. (E)-1-Arylseleno-substituted 1,3-enynes 3 were coupled with alkynylmagnesium bromides 4 in the presence of a catalytic amount of NiCl₂(PPh₃)₂ to give stereoselectively (E)-enediynes 5 in good yields.     

Stereoselective Synthesis and Diels-Alder Reactions of (Z)- and (E)-1,2-bis(Phenylthio)-1,3-Butadiene

Bromination of 3-phenylthio-2-sulfolene (2) with N-bromosuccinimide gave 2-bromo-3-phenylthio-2-sulfolene (3) which was converted mainly to 2,3-bis(phenylthio)-2-sulfolene (4) by treatment with sodium phenylthiolate. Thermal desulfonylation of 4 at different temperatures in the presence of a base (DBU) yielded stereoselectively the (Z)- and (E)-1,2-bis(phenylthio)-1,3-butadiene (6). These two geometric isomers could be thermally interconverted. The Diels-Alder reactions of 6 were also investigated. Only the (Z)-diene 6a could undergo the Diels-Alder reaction; the (E)-diene 6b was in situ converted to the Z isomer before undergoing (he Diels-Alder reaction. The reaction of 6a with N-phenylmaleimide gave the cycloaddition product 7 with complete endo selectivity, but under daylight or during chromatography it readily underwent a thioallylic rearrangement to yield 8 with inversion of configuration. The cycloaddition of 6a with methyl acrylate proceeded regiospecifically, but generating a mixture of endo and exo isomers. The endo/exo ratio could be increased by using ZnCl₂ as the catalyst.     

Synthesis and structure of lithium and rubidium compounds with 2-(diphenylacetyl)-1,3-indanedione

Complexes RbL (I) and [Li₂(C₂H₅OH)L₂] (II) (L = C₂₃H₁₅O₃) have been synthesized and their crystal structures have been studied. Both compounds have monoclinic crystals with space group P2₁/c and Z = 4; I: a = 11.632(2) Å, b = 15.154(3) Å, c = 11.457(2) Å, β = 104.34(3)°; II: a = 12.982(3)Å, b = 12.083(2) Å, c = 25.317(5) Å β = 100.11(3)°. In the structure of I, dimeric groups [Rb₂O₆] with a shared edge are linked by the ligands to give infinite layers perpendicular to the x axis and cavities that form oblong channels. In the structure of II, Li₂O₇ dimers are formed by vertex sharing. The coordination of one of the lithium atoms (Li(1)) is completed to tetrahedral by the oxygen atom of the ethanol molecule. The structure of II, like that of I, is layered.     

(1S,3S)-1,3-二苯基-1,3-丙二胺的合成

以二氯甲烷作溶剂,N-Boc保护的二氢吡唑在六甲基磷酰胺存在下与苯基格氏试剂反应,比较大量地制备了对应的四氢吡唑(4);再由4合成消旋的1,3-二苯基-1,3-丙二胺(1,总收率35%);1经L-二苯甲酰酒石酸盐拆分制得光学纯的(1S,3S)-1,3-二苯基-1,3-丙二胺,其结构经1HNMR确证。     

Methyl (E)-2-(2-phenylcyclopropylidene)acetate: Synthesis, isomerization, and reaction with 1,3-diphenyl-2-benzofuran

Treatment of 3-methyl-2-phenylcycloprop-2-ene-1-carboxylic acid with potassium tert-butoxide induced its isomerization into trans-2-methylidene-3-phenylcyclopropane-1-carboxylic acid which was converted into methyl ester, and heating of the latter for 1 h in toluene gave methyl (E)-2-(2-phenylcyclopropylidene)acetate. Thermal isomerization of methyl (E)-2-(2-phenylcyclopropylidene)acetate on prolonged heating in toluene afforded 5-methoxy-3-methyl-2-phenylfuran, and the reaction with 1,3-diphenyl-2-benzofuran resulted in [4 + 2]-cycloaddition at the exocyclic double bond.     

Heterocyclic compounds from 2-(alkoxycarbonylcyanomethylene)-1,3-dioxolanes

2-(Alkoxycarbonylcyanomethylene)-1,3-dioxolanes reacted with hydrazines and hydroxylamine to yield 1-substituted 4-alkoxycarbonyl-5-amino-3-(2′-hydroxyethoxy)pyrazoles and 4-alkoxycarbonyl-5-amino-3-(2′-hydroxyethoxy)isoxazoles respectively. With guanidine and benzamidine 2-substituted (R = NH₂, C₆H₅) 5-cyano-6-(2′-hydroxyethoxy)pyrimidin-4-ones were obtained. Reaction of 2-(cyanomethoxycarbonylmethylene)-1,3-dioxolane with 1,3-diaminopropane afforded 2-(cyanomethoxycarbonylmethylene)-1,3-hexahydro-pyrimidine whereas treatment of the same compound with 4,5-dimethyl-1,2-phenylenediamine gave 2-(cyanomethoxycarbonylmethylene)-5,6-benzimidazoline. The structures of pyrazoles and pyrimidones were assigned on the basis of ¹H-{¹H} and ¹³C-{¹H}-nOe experiments.     

Synthesis of 2-(trimethylsilyl)-1,3-butadienes

The reactions of trimethylsilyl-substituted α-allenic alcohols with lithium aluminum hydride afforded 2-(trimethylsilyl)-1,3-butadienes.     

Preparation of 1,3-Dienes,its Application to the Synthesis of (Z,E)-9,11-Tetradecadienyl Acetate and (E,E)-10,12-Hexa-decadienal: Sex Pheromones of Cotton Pests

E-2-Penten-4-yn-1-ol (3) has been utilized as a source for 1,3-diene systems by employing lithium amide induced alkylation, and curpous iodide catalysed Grignard coupling reaction as key steps. Its application for the synthesis of (Z,E)-9,11-tetradecadienyl acetate and (E,E)-10,12-hexadecadienal is described.     

Synthesis,structure, and complexing ability of fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-dicarbonyl) compounds

New fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-diketones) and 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(3-oxopropionates) were synthesized by azo coupling of the corresponding 1,3-dicarbonyl compounds with biphenyl-4,4′-bis(diazonium) dichloride. Complexing ability of the obtained bis-hydrazones was studied, and new coordination compounds of the general formula M₂L₂ [where M = Ni(II), Cu(II); L = fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-diketone)] were obtained.     

Synthesis of heterocyclic compounds from cyclohexane-1,3-diones (review)

The literature data on the synthesis of partially hydrogenated heterocyclic compounds containing a 3-oxocyclohexene structural fragment condensed with five-, six-, or seven-membered oxygen-, nitrogen-, and sulfur-containing heterorings from cyclohexane-1,3-diones and their derivatives are examined in this review.     

Synthesis and transformations of polyhedral compounds. Synthesis of 2-[quinolin-3(2)-yl]-1,3-diazaadamantanes

A number of new 1,3-diazaadamantane derivatives containing quinoline fragments on C² have been synthesized by condensation of 1,5-dialkyl-3,7-diazabicyclo[3.3.1]nonan-9-one, 1,5-dimethyl-3,7-diazabicyclo-[3.3.1]nonan-9-ol, and 1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane with 2-oxo-1,2-dihydroquinoline-3-carbaldehyde, 2-chloro- and 2-iodoquinoline-3-carbaldehyde, and quinoline-2-carbaldehyde.     

A Highly Stereoselective Synthesis of (E,E)-1,5-Dienes

Several representative 1,5-dienes were synthesized, with a high degree of regioselectivity, by a series of nitrone cycloadditions and subsequent deamination of the adducts.     

Synthesis of (±)-(E,E)-2,7-Dimethylocta-2,4-dienedioic Acid

(±-(2E,4E)-2,7-Dimethylocta-2,4-dienedioic acid ( 1 ) was synthesized efficiently from furan, employing a rhodium-carbenoid-induced furan-ring-unravelling reaction followed by an unusual NaBH₄/CeCl₃⋅7 H₂O reduction, Wittig-Horner olefination, and diester hydrolysis.