Synthesis of Novel 1,3-Dioxolane Nucleoside Analogues

Novel 1,3-dioxolane C-nucleoside analogues of tiazofurin 2-(2-hydroxymethyl-1,3-dioxolan-4-yl)-1,3-thiazole4-carboxamide as well as N-nucleoside analogues of substituted imidazoles 1-(2-hydroxymethyl-1,3-dioxolan4-yl)-4-nitroimidazole and 1-(2-hydroxymethyl-1,3-dioxolan-4-yl)-4,5-dicyanoimidazole were synthesized from methyl acrylate through a multistep procedure. Their structures were confirmed by IR,^1H NMR,^13C NMR spectraand elemental analysis.     

Oxidative Splitting of a Pyrimidine Cyclobutane Dimer:A Pulse Radiolysis Study

The oxidative splitting process of cis-syn 1,3-dimethyluracil cyclobutane dimer(DMUD) in aqueous solution was investigated using pulse radiolysis technique.The results indicated that DMUD can be splitted into 1,3-dimethyluracil(DMU) by OH radicals(OH) and Br2 radical anions(Br2^-),but not by azide radicals(N3^).The oxidative mechanisms that an H-abstracted from DMUD for OH oxidative splitting and an electron transfer from DMUD to Br2-,were suggested.Related kinetic parameters were determined.     

A Convenient and Efficient Route to 1,4-Bis（heteroaryl）-buta-1,3-diene and 4-Heteroarylbut-1-en-3-yne from 1,4-Dichlorobut-2-yne

A convenient and practical route to functionalized conjugated 1,3-enynes and 1,3-dienes is described. 1,4-Bis（heteroaryl）- 1,3-diene and 1-heteroarylbut- 1-en-3-yne derivatives were prepared from 1,4-dichloro-2-butyne and corresponding N-heteroarenes such as imidazole, pyrrole, pyrazole and indole derivatives in the presence of bases in good to high yields.     

Convenient synthesis of （4R,5R）-4,5-bis（aminomethyl）-2-isopropyl- 1,3-dioxolane

A convenient approach for the preparation of (4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane is described. The target compound via two steps is synthesized from diethyl-2,3-O-isobutylidene-D-tartrate, through ammonolysis and reduction.     

Synthesis and Crystal Structure of [EDA][Ni（dmit）2]3

The crystal structure of the compound [EDA][Ni(dmit)2]3 (EDA=2-diethylamino-1,3-dithioanylium; dmit=1,3-dithiole-2-thione-4,5-dithiolate)C25H14NNi3S32, has been determined by single crystal X-ray diffraction at 300K. The crystal is triclinic with space group P, a=11.252, b=12.192(2), c=20.055(6) , α=108.127(2), β=106.287(8), γ=90.005(9)°; V=2498.3(3) 3, Z=2, Mr=1530.38, Dc=2.03(2) g/cm3. Final R and Rw values were 0.0603 and 0.0704, respectively. The structure consists of thick layers of stacked Ni(dmit)2 entities separated by EDA cations. This salt shows semiconducting behaviour with room temperature conductivity of 0.2 Scm-1 and activation energy of 0.11 eV.     

Hydrothermal Synthesis and Structural Characterization of Two Zinc Coordination Polymers of 1,2‐Di(4‐pyridyl)ethylene and Benzenedicarboxylate

Hydrothermal reactions of Zn(NO3)2•6H2O with 1,2-di(4-pyridyl)ethylene (dpe) and 1,4-benzenedicarboxylate (1,4-BDC) or 1,3-benzenedicarboxylate (1,3-BDC) in water gave rise to two new metal-organic coordination polymers, [Zn(1,4-BDC)(dpe)]n (1) and [Zn4O(1,3-BDC)3(dpe)]n (2). Both compounds were characterized by elemental analysis and IR spectroscopy, and their structures were determined by single crystal X-ray diffraction. 1 displays a rare 5-fold interpenetrating 66-diamondoid framework while 2 possesses an interlocked 3D network formed by inclined interpenetration of 2D (4,4) networks that are constructed by μ4-oxo tetrazinc Zn4O cores and the bridging dpe and 1,3-BDC ligands. Thermal and photoluminescent properties of 1 and 2 were also investigated.     

Synthesis and electrochemical properties of a chiral silyl-substituted tetrathiafulvalene derivative

A new chiral tetrathiafulvalene(TTF) derivative and related silyl-substituted 1,3-dithiole-2-(thi)one compounds were synthesized and characterized by ~1H NMR,~(13)C NMR,MS and IR spectra.Single crystal structure of the silyl-substituted 1,3-dithiole-2-one revealed the high degree of conjugation of the fivemembered ring moiety in the compound.The electrochemical properties of the new TTF derivative were studied by cyclic voltammetry and the results indicated that the electron-donating ability of the chiral TTF derivative was similar to that of BEDT-TTF.The △E value for the new TTF derivative was smaller than those for TTF and BEDT-TTF,indicative of decreased Coulombic repulsion in the dicationic redox state.Formation of charge-transfer(CT) complex between the new donor and electron acceptor 2,3-dichloro-5,6-dicyano-l,4-benzoquinone(DDQ) was demonstrated.     

Highly Stereoselective Synthesis of Phenylseleno- and p-Tolylsulfonyl Substituted 1,3-Dienes from Functionalized Allyl Alcohols

Introduction Heteroatom-substituted 1,3-dienes have been exten-sively studied because of their marked abilities to con-struct highly functionalized ring systems in cycloaddi-tions.1 For example, Danishefsky2 developed 1-methoxy-3-trimethyl-siloxy-buta-1,3-diene which has led to many creative applications in complex organic synthesis. Padwa et al.3 demonstrated that 1,3- and 2, 3-bis(phenyl-sulfonyl)-1,3-butadienes are versatile building blocks in organic synthesis via reactions such as [4+2]-c…     

Two Praseodymium Coordination Complexes with 1,3-Phenylenediacetate:Structural Diversity Tuned by Auxiliary Ligands

Two new coordination complexes, [Pr(1,3-pda)0.5(nbca)2(H2O)2](1) and [Pr2(1,3-pda)3(2,2ˊ-bpy)2(H2O)2](2)(H2pda = 1,3-phenylenediacetic acid, Hnbca = 5-nitro [1,1ˊ-biphenyl]-3-carboxylic acid, 2,2ˊ-bpy = 2,2ˊ-bipyridine), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. In 1, the nbca ligands bridge the Pr3+ ions to form a 1D chain. Moreover, these 1D chains are united together through the 1,3-pda ligands to afford a 2D layer. In contrast, due to a different auxiliary ligand, complex 2 is a 2D layer linked through only bridging deprotonated 1,3-pda. Thermal stabilities and solid fluorescence properties of 1 and 2 were also studied.     

High extraction ability of 1,3-dialkynyl calixarene towards mercury（Ⅱ） ion

The reaction of 1,3-dipropyn-2-yloxycalix[4]arene with mercury(II)acetate could give mercury-containing alkynyl calixarenepolymer.The extraction behavior of 1,3-dipropyn-2-yl-oxycalix[4]arene towards mercury(II)ion was examined.When the moleratio of Hg~(2 )/calixarene was 1:1,the extractive percent can reach to 99.1%,and the extraction capacity was up to 431 mg/g.It couldalso decrease the Hg~(2 )concentration from 5 to 0.85 mg/L,which was only 17%of the national standard of effluent and satisfied thenational standard of drinking water.The extraction process included chemical reaction.     

Reaction of 1,3-Dioxanes with Acetone Cyanohydrin

The reaction of 4-phenyl- and 4,4-dimethyl-1,3-dioxanes with acetone cyanohydrin leads to hydrolytically unstable 2-(1-hydroxy-1-methylethyl)-5,6-dihydro-1,3-oxazines, which are readily saponified in alkaline medium to the corresponding 1,3-amino alcohols.     

Reactions of 1,3-dioxacyclanes with acid halides a new synthesis for ω-halohydrine esters

Reaction of 1,3-dioxolanes and 1,3-dioxanes with aliphatic acid chlorides and bromides yields 2- or 3-halohydrine esters.

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Reaktionen von 1,3-Dioxacyclanen mit Säurehalogeniden. Eine neue Synthese für -Halogenhydrinester (Kurze Mitteilung)

Zusammenfassung Die Reaktion von 1,3-Dioxolanen und 1,3-Dioxanen mit aliphatischen Säurechloriden ergab 2- bzw. 3-Halogenhydrinester

     

3(1,3-Heterazolidin-3-yl-methyl)-1,3-oxazolidines and their reduction with borane–THF

Preparation of bis-heterazolidines bonded by a CH₂, CH₂–S–CH₂ or CH₂SCH₂SCH₂ groups through their nitrogen atoms is reported: 3-(1,3-oxazolidin-3-ylmethyl)-1,3-oxazolidine 1, 3-(4,4-dimethyl-1,3-oxazolidin-3-ylmethyl)-1,3-oxazolidine 2, 3-(1,3-diazolidin-3-ylmethyl)-1,3-diazolidine 3, 3-(1,3-thiazolidin-3-ylmethyl)-1,3-thiazolidine 4, 3-(1,3-thiazolidin-3-ylmethylsulfanylmethyl)-1,3-thiazolidine 5 and 3-(1,3-oxazolidin-3-ylmethylsulfanylmethyl-sulfanylmethyl)-1,3-oxazolidine 6. The solid state structures of 4 and 5 were determined by X-ray diffraction analyses. BH₃–THF reduction reactions of compounds 1–6 were investigated. N→BH₃ mono- and di-adducts of 1–6 were prepared and their structures calculated (ab initio 3-21G*).     

New Approach to the Synthesis of 1,3-Chloroisothiocyanatoalkanes. Synthesis of Tetrahydro-1,3-thiazine-2-thiones and 2-Alkylamino-5,6-dihydro-1,3-thiazines

A method was developed to prepare 1,3-chloroisothiocyanatoalkanes by reducing 1,3-isothiocyanato ketones using sodium borohydride at pH ~7 and subsequent treatment of the resultant 1,3-isothiocyanato alcohols with thionyl chloride. The reaction of 1,3-chloroisothiocyanatoalkanes with sodium hydrosulfide or amines gives substituted tetrahydro-1,3-thiazine-2-thiones or 2-amino-5,6-dihydro-1,3-thiazines.     

Synthesis and stereochemistry of new 1,3-thiazolidine systems based on 2-amino-2-(mercaptomethyl)propane-1,3-diol: 4,4-bis(hydroxymethyl)-1,3-thiazolidines and c-5-hydroxymethyl-3-oxa-7-thia-r-1-azabicyclo[3.3.0]octanes

The thiaminalisation of 2-amino-2-(mercaptomethyl)propane-1,3-diol [‘2-(hydroxymethyl)cysteinol’] with aryl(di)aldehydes is reported. The resulting new class of 2-aryl-4,4-bis(hydroxymethyl)-1,3-thiazolidines is investigated by NMR and IR spectroscopy in tandem with DFT calculations, permitting structural assignments that are discussed in terms of conformational analysis, anomeric effects and ring-chain tautomerism. These acquired data are subsequently exploited. After treatment with formaldehyde, the subsequent (double) regio- and diastereoselective oxaminalisation of the 1,3-thiazolidine building-block affords the first non-symmetric series of a thiazolidin-oxazolidine fused system singly functionalised at the C-5 position. An unexpected rearrangement, which consists of the partial relocation of the Ar ligand from the 1,3-thiazolidine to the 1,3-oxazolidine ring, is observed as a major influence on the substitution of the Ar ring. The first single crystal X-ray analysis of the title bicyclic system, which discloses the homo- and/or heterochiral non-bonding interactions, is also presented.     

Regioselective synthesis of polysubstituted phenol derivatives from Baylis-Hillman adducts via [3+3] annulation strategy

Polysubstituted phenol derivatives were synthesized from the acetates of Baylis-Hillman adducts and dimethyl 1,3-acetonedicarboxylate (DMAD) in a one-pot reaction via the sequential S_N2′ reaction, aldol condensation, and 1,3-H shift process.     

α-Ureidoalkylation of 1,3-bis(hydroxymethyl)-imidazolidin-2-one

The α-ureidoalkylation of imidazolidine-2,4-dione, urea, carboxylic acid amides, and sulfonamides has been studied using 1,3-bis(hydroxymethyl)-imidazolidin-2-one as ureidoalkylating agent. Methods have been developed for the synthesis of 1,3-bis(2,4-dioxoimidazolidin-1-ylmethyl)-, 1,3-bis(acetylaminomethyl)-, 1,3-bis(benzoylaminomethyl)-, 1,3-bis(phenylsulfonylaminomethyl)-, and 1,3-bis(p-toluenesulfonylaminomethyl)imidazolidin-2-ones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1655–1659, November, 2007.     

Synthesis of 1,3-bis(N,N-difluoroamino)adamantane: addition of difluoramino radicals to 1,3-dehydroadamantane

1,3-Dehydroadamantane undergoes a facile reaction with tetrafluorohydrazine to give 1,3-bis(N,N-difluoroamino)adamantane, the product of 1,3-NF₂ radical addition.     

HETEROCYCLIC CATIONS WITH DELOCALISED PI-SYSTEMS AND SHORT INTRAMOLECULAR SULFUR… SULFUR CONTACTS: THE STRUCTURES OF TWO DERIVATIVES OF THE 2-(1,3-DITHIOL-2-YLIDENEMETHYL)-1,3-DITHIOLIUM CATION

Abstract

The effective size of bonded divalent sulfur in S…S contacts is a function of the orientation of the groups, with the shortest contacts occurring when the groups are coplanar. A lower limit for the loner is indicated by the structures of the 2-(1,3-benzodithiol-2-ylidenemethyl)-1,3-benzodithiolium and 2-(1,3-dithiolan-2-ylidenemethyl)-1,3-dithiolanium cations, 2 and 3. These show almost mm symmetry with all four sulfur atoms involved in stabilisation of the positive charge. Short intramolecular sulfur… sulfur contact distances, 0.5–0.7 Å within the sum of traditional van der Waals radii, and maximised by in-plane angular distortions, indicate a lower limit to the effective size of the bonded divalent sulfur atom of ca. 1.45 Å.     

Dithiocarboxylierung von α-Stickstoff-Carbanionen

Summary Dithiocarbamic acid esters1 with CH-acidic methylene group adjacent to nitrogen react in the system dimethylformamide +2 equivalent sodiumtert. butoxide with carbon disulphide yielding 1,3-thiazoline-2-thiones3. 2,5-Bis(alkylthio)-1,3,-thiazoles6 are available via dithiocarboxylation of isothiocyanate5.