Synthesis of N-Aryl-2- （1＇, 6＇-dihydro-6＇-pyridazinone-3＇-carbonyl） Thiosemicarbazides and Their Related Heterocyclic Compounds

1,6-Dihydro-3-hydrozinocarbonyl-6-pyridazinone (compound 2) were prepared from α-ketoglutaric acid and hydrazine hydrate. A series of N-aryl-2-(1‘,6‘-dihydro-6‘-pyridazinone-3‘-carbonyl) thiosemicarbazides 3a-3f were synthesized from the reaction of aryl isothiocyanates with compound 2. The terminal compounds 1,3, 4-thiadiazole, 1,3,4-oxadiazole and 1,2, 4-triazol-5-thione derivatives were cyclized from compounds 3a-3f. Their structures were confirmed by IR,^1H NMR, MS and elemental analyses.     

Synthesis of N-Aryl-2- (1'' , 6'' -dihydro-6'' -pyridazinone-3''-carbonyl) Thiosemicarbazides and Their Related Heterocyclic Compounds

1,6-Dihydro-3-hydrozinocarbonyl-6-pyridazinone(compound 2) were prepared from α-ketoglutaric acid and hydrazine hydrate. A series of N-aryl-2-(1' ,6'-dihydro-6'-pyridazinone-3'-earbonyl) thiosemicarbazides 3a-3f were synthesized from the reaction of aryl isothiocyanates with compound 2. The terminal compounds 1,3, 4-thiadiazole, 1,3,4-oxadiazole and 1,2, 4-triazol-5-thione derivatives were cyclized from compounds 3a-3f. Their structures were confirmed by IR, 1H NMR, MS and elemental analyses.     

Synthesis with nitriles: synthesis of some new mercaptopyridazine, mercaptopyridazino[1,6-a]quinazoline and thiophene derivatives

2-(1-(4-Bromophenyl)-2-thiocyanatoethylidene)malononitrile (3) undergoes azo coupling with diazotized aromatic amines to afford arylhydrazone derivatives, which are readily cyclized to afford the corresponding 3(2H)-pyridazinimine derivatives upon reflux in aqueous NaOH. Under similar condition an o-cyanoarylhydrazone derivative was cyclized into 6H-pyridazino[1,6-a]quinazolin-6-imine, which in turn was easily transformed into 6H-pyridazino[1,6-a]quinazolin-6-one on reflux in ethanolic/HCl. Compound 3 afforded substituted 5-acetylthiophene derivatives upon reflux in AcOH/HCl mixtures.     

Formation of Three-Membered Rings by S(H)i Displacement. Reverse of Cyclopropyl Ring Opening(1)

The general methods, photoinitiated or peroxide-initiated free radical chain additions of halomethanes to olefins, yield 1,2-addition products at temperatures ranging from 20 to 100 degrees C. At lower temperatures, -42 to -104 degrees C, a competitive reaction, subsequent to the addition of CCl(2)X(*), yields alkylcyclopropanes. The reactions of 1-octene or 1-hexene and 1-methylcyclohexene with atomic hydrogen carried out in the presence of several transfer agents (CCl(4), CCl(3)Br, CCl(2)Br(2)) initiate a radical chain addition of CCl(2)X(*) and yield cyclized materials resulting from the S(H)i displacement of halogen by a carbon-centered radical. The radical displacement of a halogen on carbon, the reverse of homolytic displacement on cyclopropyl carbon, is dominant at low temperatures. The rate constants for cyclization (k(c)) vs transfer with halomethane (k(t)) showed isokinetic temperatures of -46 degrees C (CCl(4), 1-hexene); -35 degrees C (CCl(4), 1-methylcyclohexene). The isokinetic temperatures for the reactions of the two substrates carried out in the presence of BrCCl(3) were calculated as -204 degrees C (1-octene) and -109 degrees C (1-methylcyclohexene).     

钝化萘衍生物的磺化反应研究

研究了带吸电子取代基的一系列钝化萘衍生物与SO~3进行的磺化反应, 用^1H NMR分析反应混合物的组成.1-萘磺酸以71:20:9的比例产生1,5-, 1,6-和1,7-萘二磺酸, 进一步磺化得到1,3,5-, 1,3,6-萘三磺酸和1,3,5,7-萘四磺酸. 1-萘甲醛的单硫化得到比例为55:9:6:30的5-, 6-,7-和8-磺酸取代物. 1-苯甲酮萘则以83:11:6的比例得到5-,6-,和7-磺酸取代物. 1-硝基萘仅得到5位磺化产物. 1-萘甲酸和1-萘甲酸甲酯得到5位和8位取代产物. 所有的2位取代萘衍生物均先得到5和8位取代产物. 提出了生成SO~3络合物及迫位磺化的历程.     

Functionalization of monofluoroallene and the synthesis of aryl-substituted conjugated fluorodienes

[reaction: see text] 4-Fluoroallenol 3a, prepared from 1, cyclized easily to 4 but preserved its fluoroallenyl integrity under oxidation and S(N)2 displacement to yield aldehyde, amine, mesylate, and halide 6. Allylic isomerization yielded 2-halo-1-fluoro-1,3-butadiene 7, which underwent a Suzuki coupling to give aryl-substituted conjugated diene 8.     

Poly(epsilon-caprolactone)-poly(oxyethylene) multiblock copolymers bearing along the chain regularly spaced pendant amino groups

Poly(epsilon-caprolactone) (PCL) macromers (M(n) = 1.7-3.8 kDa) which contain one Z-protected -NH2 group per chain were synthesized by ring-opening polymerization of epsilon-caprolactone in the presence of Sn(oct)2 using as initiator a diamine prepared by condensation of N-Boc-1,6-hexanediamine and N(alpha)-Boc-N(epsilon)-Z-L-Lysine. The coupling of these macromers with -COCl end-capped poly(oxyethylene) (PEO), M(n) = 1.0 kDa, afforded amphiphilic multiblock poly(ether ester)s (PEEs) which have, along the chain, regularly spaced pendant protected amino groups. Deprotection, accomplished without chain degradation, yielded -NH2 groups available for further reactions. The molecular structure of macromers and PEEs was investigated by 1H NMR and SEC. DSC and WAXS analyses showed that macromers and copolymers were semicrystalline and their T(m) increased with increase in the molecular weight of PCL segments. The inherent viscosity values (0.25-0.30 dL x g(-1)), together with SEC analysis results, indicated moderate polymerization degrees.     

Synthesis and characterization of a [3-15N]-labeled cis-syn thymine dimer-containing DNA duplex

Cis-syn thymine dimers are the major photoproducts of DNA and are the principal cause of mutations induced by sunlight. To better understand the nature of base pairing with cis-syn thymine dimers, we have synthesized a decamer oligodeoxynucleotide (ODN) containing a cis-syn thymine dimer labeled at the N3 of both T's with 15N by two efficient routes from [3-15N]-thymidine phosphoramidite. In the postsynthetic irradiation route, an ODN containing an adjacent pair of [3-15N]-labeled T's was irradiated and the cis-syn dimer-containing ODN isolated by HPLC. In the mixed building block route, a mixture of cis-syn and trans-syn dimer-containing ODNs was synthesized from a mixture of [3-15N]-labeled thymine dimer phosphoramidites after which the cis-syn dimer-containing ODN was isolated by HPLC. The N3-nitrogen and imino proton signals of an (15)N-labeled thymine dimer-containing decamer duplex were assigned by 2D 1H-15N heterocorrelated HSQC NMR spectroscopy, and the 15N-1H coupling constant was found to be 1.8 Hz greater for the 5'-T than for the 3'-T. The larger coupling constant is indicative of weaker H-bonding that is consistent with the more distorted nature of the 5'-base pair found in solution state NMR and crystallographic structures.     

叔丁氧羰基单端基保护己二胺的合成

以己二胺为原料，叔丁氧羰基酸酐(Boc2O)为保护剂，合成了Boc单端基保护己二胺。并用IR和^1H NMR对产物进行了表征。该化合物可用作氨基酸的N-羰基环内酸酐(NCA)开环聚合法合成结构明晰的两嵌段聚氨基酸的引发剂，因而具有良好的应用前景。     

Geminate charge recombination in liquid alkane with concentrated CCl4: effects of CCl4 radical anion and narrowing of initial distribution of Cl-

Dynamics of radical cations and electrons in an admixture of a linear saturated hydrocarbon (n-dodecane) and halocarbon (carbon tetrachloride, CCl(4)) were investigated by picosecond electron beam pulse radiolysis. The decay of thermalized electrons (e(th)(-)) observed in infrared transient photoabsorption were simply accelerated by the addition of CCl(4), giving a high rate constant of 2.3 × 10(11) mol(-1) dm(3) s(-1). The decrease of the initial yield of e(th)(-) was quantified by C(37) (50 mmol), which is linked to the reaction of epithermal electrons (e(-)) with CCl(4). In contrast, the n-dodecane radical cation (RH(2)(?+)) monitored in the near-infrared indicated a convex-type dependence of the decay rate on CCl(4) concentration, although the initial yield of RH(2)(?+) remained almost constant up to a much higher CCl(4) concentration. The decay of RH(2)(?+) was analyzed by Monte Carlo simulations of geminate ion recombination with e(th)(-), chlorine anion (Cl(-)) formed via dissociative electron attachment, and CCl(4) radical anion. The results showed a good agreement with the experiments by considering two assumptions: (1) CCl(4) radical anion formed via e(th)(-) attachment and (2) narrowing of the initial distribution of Cl(-). The decrease in the initial yield of RH(2)(?+) at high CCl(4) concentration was well explained by immediate decomposition of CCl(4)(?+) to CCl(3)(+) and hole transfer from CCl(4)(?+) to adjacent RH(2) without diffusive motion of the reactants. Time-dependent density functional theory supported the spectroscopic assignment of intermediate species in the n-dodecane/CCl(4) system. The present results would be of help in understanding the electron capture reaction in multicomponent systems such as a chemically amplified resist in lithography.     

Structures of a tetradentate ferrocenyl ligand and its oxorhenium(V) complex in solution and in the solid state

The novel ferrocenyl ligand rac-1,6-diferrocenyl-N,N'-bis(2-hydroxypropyl)-2,5-diazahexane (1, H(2)L) was synthesized from ferrocenylcarboxaldehyde and ethylenediamine followed by the reduction of the Schiff base with LiAlH(4) and subsequent N-alkylation with 1,2-propyleneoxide. The dianion of H(2)L reacted with [ReO(PPh(3))(2)Cl(3)], and the product was treated with NH(4)PF(6) to afford the complex [ReO(L-N(2)O(2))PPh(3)]PF(6) (2). Both the ferrocenyl ligand and the complex were characterized in solution by NMR spectroscopy and in the solid state by single-crystal X-ray diffraction studies. NMR investigations reveal two solvent-dependent isomers for the ferrocenyl ligand in solution of which the major form is the more ordered one. The cation of 2 displays a nonsymmetrically coordinated N(2)O(2) ligand.     

水溶性共轭聚电解质的制备及在有机电致变色器件中的应用

制备了聚噻吩电解质聚[3-(1'-丙氧基-3'-磺酸)噻吩](PTH-n₃-SO₃H). 以铂线和ITO玻璃作为电极, PTH-n₃-SO₃H的水溶液作为支持电解质, 分别以齐聚噻吩衍生物5,5"'-双醛基-2,2': 5',2": 5",2"'-四噻吩(4T-2CHO)和5,5"'-双氰基-2,2': 5',2": 5",2"'-四噻吩(4T-2CN)薄膜作为电致变色活性层, 组装了有机电致变色器件. 研究了4T-2CHO和4T-2CN的电致变色性能, 同时考察了PTH-n₃-SO₃H水溶液作为支持电解质在有机电致变色器件中的应用. 研究发现, 当进行电化学掺杂和去掺杂时, 4T-2CHO膜发生从黄色到蓝绿色的可逆变化, 4T-2CN膜发生从淡黄色到蓝色的可逆变化. 结果表明, PTH-n₃-SO₃H水溶液可以作为支持电解质用于有机电致变色器件.     

简便合成3,3'-联-1,6-亚甲基桥[10]轮烯

以1,6-二甲酰基环庚三烯为原料通过10π电子环化反应等3步反应制备了3-溴代-1,6-亚甲基桥[10]轮烯, 通过3-溴代-1,6-亚甲基桥[10]轮烯的碱诱导的偶联反应, 简便地合成3,3'-联-1,6-亚甲基桥[10]轮烯, 并用NMR, MS等波谱进行了表征.     

Vicinal 1H-1H NMR coupling constants from density functional theory as reliable tools for stereochemical analysis of highly flexible multichiral center molecules

A protocol for stereochemical analysis, based on the systematic comparison between theoretical and experimental vicinal (1)H-(1)H NMR coupling constants, was developed and applied to a series of flexible compounds (1-8) derived from the 6-heptenyl-5,6-dihydro-2H-pyran-2-one framework. The method included a broad conformational search, followed by geometry optimization at the DFT B3LYP/DGDZVP level, calculation of the vibrational frequencies, thermochemical parameters, magnetic shielding tensors, and the total NMR spin-spin coupling constants. Three scaling factors, depending on the carbon atom hybridizations, were found for the (1)H-C-C-(1)H vicinal coupling constants: f((sp3)-(sp3)) = 0.910, f((sp3)-(sp2)) = 0.929, and f((sp2)-(sp2))= 0.977. A remarkable correlation between the theoretical (J(pre)) and experimental (1)H-(1)H NMR (J(exp)) coupling constants for spicigerolide (1), a cytotoxic natural product, and some of its synthetic stereoisomers (2-4) demonstrated the predictive value of this approach for the stereochemical assignment of highly flexible compounds containing multiple chiral centers. The stereochemistry of two natural 6-heptenyl-5,6-dihydro-2H-pyran-2-ones (14 and 15) containing diverse functional groups in the heptenyl side chain was also analyzed by application of this combined theoretical and experimental approach, confirming its reliability. Additionally, a geometrical analysis for the conformations of 1-8 revealed that weak hydrogen bonds substantially guide the conformational behavior of the tetraacyloxy-6-heptenyl-2H-pyran-2-ones.     

Synthesis and configurational assignment of the amino alcohol in the eastern fragment of the GE2270 antibiotics by regio- and stereoselective addition of 2-metalated 4-bromothiazoles to alpha-chiral electrophiles

A synthesis of the eastern fragment of the thiazole peptide GE2270 A (1) has been developed. The synthetic approach relies on the regioselective functionalization of 2,4-dibromothiazole (5) via metalation and nucleophilic addition (at C2) or palladium-mediated cross-coupling (at C2 or C4). The stereochemistry at the N-bearing stereocenter was established by coupling of 2-metalated 4-bromothiazoles (4) to enantiomerically pure mandelic acid derivatives. Both the erythro (2) and threo (3) configurated amino alcohols were prepared with high diastereoselectivities depending on the electrophile employed. More specifically, the threo-configurated (S,R)-4-bromothiazolyl beta-amino alcohol 6 was synthesized from O-TBS protected (R)-mandelonitrile in 62% yield. Its N-PMB protected (R,S)-enantiomer 20 was obtained from O-TBS protected (S)-mandelic aldehyde in 67% yield. The erythro-configurated (S,S)-4-bromothiazolyl beta-amino alcohol 29 was prepared from O-TBS protected (S)-ethyl mandelate in four steps and 33% overall yield. The bithiazole moiety in the desired products 2 and 3 was finally established by the regioselective Negishi coupling of 2,4-dibromothiazole (5) and the 4-zincated, N-Boc protected thiazole derivatives of the diastereomeric 4-bromothiazolyl beta-amino alcohols 6 and 29.     

Spin�Corbit ab initio study of two low-lying states of chloroiodomethane cation

Spin?Corbit coupling plays a crucial role in the determination of molecular structure and calculation of vibrational frequencies of CH₂ClI⁺. We performed the geometry optimizations and vibrational frequency calculations of both the lower and upper spin?Corbit (SO) states using an ab initio SO method based on multiconfigurational wave function. The multistate complete active space perturbation theory second-order SO (MS-CASPT2-SO) method reasonably describes the structures of the lower SO state, yielding the C?CI distance and the I?CC?CCl angle close to the experimental values. The geometrical parameters of the upper SO state is quite similar to that of the lower SO state, whereas structures of two states differ substantially in calculations prior to the introduction of SO coupling. The MS-CASPT2-SO method reproduces the difference between the lower and upper SO states for the I?CC?CCl bending frequency. The vibrational frequencies calculated by MS-CASPT2-SO generally overestimate in comparison with the experiments. The energy gap between the two SO states calculated by MS-CASPT2-SO is reasonably close to the experimental value. To the best of our knowledge, this is the first attempt to calculate vibrational frequencies of two SO states of CH₂ClI⁺, and the first time to apply MS-CASPT2-SO method to the geometry optimization and vibrational frequency calculation of polyatomic molecule.     

Theoretical understanding on the v(1)-SO4(2-) band perturbed by the formation of magnesium sulfate ion pairs

The factors determining the spectroscopic characteristics of the v(1)-SO4(2-) band of the MgSO4 ion pairs are discussed via ab initio calculation, including coupling effect, hydrogen bonding effect, and direct contact effect of Mg2+ with SO4(2-). With the calculation of the heavy water hydrated contact ion pairs (CIP), the overlap between the librations of water and the v(1)-SO4(2-) band can be separated, and thus the coupling effect is abstracted, and this coupling effect leads to a blue shift for the v(1)-SO4(2-) band of 5.6 cm(-1) in the monodentate CIP and 3.6 cm(-1) in the bidentate CIP. The hydrogen bonding between each water molecule without relation to Mg2+ and the sulfate ion makes the v(1)-SO4(2-) band blue shift of 3.7 cm(-1). When the outer-sphere water around Mg2+ are hydrogen bonded between SO4(2-) and Mg2+, it will make the largest disturbance to the v(1)-SO4(2-) band. Moreover, the inner-sphere water can affect the v(1)-SO4(2-) band conjunct with the direct contact of Mg2+ with SO4(2-), showing a blue shift of 14.4 cm(-1) in the solvent-shared ion pair, 22.6 cm(-1) in the monodentate CIP, 4.3 cm(-1) in the bidentate CIP, and 21.4 cm(-1) in the tridentate CIP. At last, the Raman spectral evolution in the efflorescence production process is tried to be rationalized. The shoulder at 995 cm(-1) is attributed to the monodentate CIP with 2-3 outer-sphere water molecules, whereas the new peak at 1021 cm(-1) at high concentration is assigned to the formation of aqueous triple ion.     

On‐Surface Domino Reactions: Glaser Coupling and Dehydrogenative Coupling of a Biscarboxylic Acid To Form Polymeric Bisacylperoxides

Herein we report the on‐surface oxidative homocoupling of 6,6′‐(1,4‐buta‐1,3‐diynyl)bis(2‐naphthoic acid) (BDNA) via bisacylperoxide formation on different Au substrates. By using this unprecedented dehydrogenative polymerization of a biscarboxylic acid, linear poly‐BDNA with a chain length of over 100 nm was prepared. It is shown that the monomer BDNA can be prepared in situ at the surface via on‐surface Glaser coupling of 6‐ethynyl‐2‐naphthoic acid (ENA). Under the Glaser coupling conditions, BDNA directly undergoes polymerization to give the polymeric peroxide (poly‐BDNA) representing a first example of an on‐surface domino reaction. It is shown that the reaction outcome varies as a function of surface topography (Au(111) or Au(100)) and also of the surface coverage, to give branched polymers, linear polymers, or 2D metal–organic networks.     

稀土配合物的研究 I: 镧系元素与4-酰代-双吡唑啉酮及1,10-二氮杂菲的混配配合物的合成及表征

用镧系硝酸盐与1,6-双(1'-苯基-3'-甲基-5'-氧代吡唑-4'-基)-1,6-己二酮(1,H2L)和1,10-二氮杂菲(2, Phen)在乙醇-水溶液中, 于PH5-6时合成了12种新的固态配合物Ln2L3Phen2. 4H2O(Ln=Pr, Nd, Sm-Lu)。用元素分析、水份及配体分析、红外、紫外,质子核磁共振、荧光光谱和热分析鉴定了所有的配合物, 从而推测, 可能L是四啮配体,Phen是二啮配体。     

Synthesis of nitrogen-containing heterocycles. 7 Reaction of aliphatic diaminomethylenehydrazones with hindered ethoxymethylenecyanoacetate

Aliphatic diaminomethylenehydrazones 1 were reacted with ethyl 2-cyano-3-ethoxy-2-pentenoate 2 to give a number of heterocycles in low to moderate yields, according to the substitution pattern and the size of substituent. When 1 carried a single methyl group on the terminal nitrogen, it gave preferentially 6-oxo-1,6-dihydropyrimidines 4 incorporating N(4) into the ring. In contrast, the reaction between 1c or 1d and 2 led to 6-imino- and 6-oxo-1, 6-dihydropyrimidines 7 and 8 along with 3 . When the alkylidene moiety was bulky, 1e and 1f , the similar reaction gave 3 in high yields without any cyclized product. Upon exposure to acid, compound 3 yielded 6-oxo-1,6-dihydropyrimidines 6 , [1,2,4]triazolo[1,5-c]pyrimidine-8-carboxylate 5 and N-alkenyl-1,2,4-triazoles 9 in addition to 7 and 8 in proportions dictated by the nature of the substituents of 1 . The structural assignment and reaction mechanism are discussed.