Reaction mechanisms and structural characterization of the reactive intermediates observed after the photolysis of 3-(hydroxymethyl)benzophenone in acetonitrile, 2-propanol, and neutral and acidic aqueous solutions

Nanosecond time-resolved resonance Raman (ns-TR(3)) spectroscopy was employed to investigate the photoinduced reactions of 3-(hydroxymethyl)benzophenone (1) in acetonitrile, 2-propanol, and neutral and acidic aqueous solutions. Density functional theory calculations were utilized to help the interpretation of the experimental spectra. In acetonitrile, the neutral triplet state 1 [denoted here as (m-BPOH)(3)] was observed on the nanosecond to microsecond time scale. In 2-propanol this triplet state appeared to abstract a hydrogen atom from the solvent molecules to produce the aryphenyl ketyl radical of 1 (denoted here as ArPK of 1), and then this species underwent a cross-coupling reaction with the dimethylketyl radical (also formed from the hydrogen abstraction reaction) to form a long-lived light absorbing transient species that was tentatively identified to be mainly 2-(4-(hydroxy(3-(hydroxymethyl)phenyl)methylene)cyclohexa-2,5-dienyl)propan-2-ol. In 1:1 H(2)O:CH(3)CN aqueous solution at neutral pH, (m-BPOH)(3) reacted with water to produce the ArPK of 1 and then underwent further reaction to produce a long-lived light absorbing transient species. Three photochemical reactions appeared to take place after 266 nm photolysis of 1 in acidic aqueous solutions, a photoreduction reaction, an overall photohydration reaction, and a novel photoredox reaction. TR(3) experiments in 1:1 H(2)O:CH(3)CN aqueous solution at pH 2 detected a new triplet biradical species, which is associated with an unusual photoredox reaction. This reaction is observed to be the predominant reaction at pH 2 and seems to face competition from the overall photohydration reaction at pH 0.     

天然产物Combretastatin A-1和Combretastatin B-1的合成

基于Perkin反应策略合成了具有强效抗肿瘤、抗血管活性的天然产物Combretastatin A-1(CA1)和Combretastatin B-1(CB1).以2,3,4-三羟基苯甲醛(1)为起始物, 经单甲基化反应得到2,3-二羟基-4-甲氧基苯甲醛(2), 再经酚羟基保护得到2,3-二异丙基-4-甲氧基苯甲醛(3), 该化合物与3,4,5-三甲氧基苯乙酸(4)发生Perkin反应分离得到E-2-(3,4,5-三甲氧基苯基)-3-(2',3'-二异丙氧基-4'-甲氧基)丙烯酸(E-5), 经脱羧反应得到Z-3,4,4',5-四甲氧基-2',3'-二异丙氧基二苯乙烯(6), 最后经脱保护反应得到CA1.另外, 将E-2-(3,4,5-三甲氧基苯基)-3-(2',3'-二异丙氧基-4'-甲氧基)丙烯酸(E-5)脱去保护基得到E-2-(3,4,5-三甲氧基苯基)-3-(2',3'-二羟基-4'-甲氧基)丙烯酸(7), 该化合物经脱羧-异构化反应得到E-3,4,4',5-四甲氧基-2',3'-二羟基二苯乙烯(E-CA1), 最后经催化氢化得到CB1.     

氘代AZD9291的合成

吲哚和2,4-二氯嘧啶经偶联反应制得3-(2-氯嘧啶-4-基)-1H-吲哚(1); 1与CD₃I 经取代反应制得3-(2-氯嘧啶-4-基)-1-(甲基-d₃)-吲哚(2); 2经两步亲核取代反应制得N′-(2-二甲基氨基乙基)-2-甲氧基-N′-甲基-N-{［4-(1-(甲基-d₃)吲哚-3-基)］嘧啶-2-基}-5-硝基苯-1,4-二胺(4); 4经还原反应后,与氯丙酰氯发生缩合反应合成了氘代AZD9291,总收率8.5%,其结构经¹H NMR, ¹³C NMR和ESI-MS表征。     

2-取代吲哚的染料敏化光氧化反应

2-苯基吲哚 (1a) 在甲醇中的染料敏化光氧化反应给出2-苯基-2-(2'-苯基-3'-吲哚基)二氢吲哚-3-酮 (2a) 和2-甲氧基-2-苯基二氢吲哚-3-酮 (4a), 相应N-甲基取代产物由1-甲基-2-苯基吲哚 (1b) 的类似反应获得。发现反应产物分布随吲哚 (1) 的浓度和介质酸度的变化而变化。对反应机理进行了推测, 其中当1a的反应在乙腈中进行时, 分离到了相应的反应中间体: 2-苯基-3H-吲哚-3-酮 (3a)。     

Kinetic study of the daytime atmospheric fate of (z)-3-hexenal

Rate coefficients for three daytime atmospheric reactions of (Z)-3-hexenal (3HA)-photolysis (J(1)), reaction with OH radicals (k(2)), and reaction with ozone (k(3))-were measured at 760 Torr and 298 K using a 6 m(3) photochemical reaction chamber. The UV absorption cross sections (σ(3HA)(λ)) were obtained in the wavelength range 240-350 nm. The photodissociation rate of 3HA relative to that of NO(2) was measured by a solar simulator at 760 Torr and was determined to be J(1)/J(NO2) = (4.7 ± 0.4) × 10(-3). Using the obtained σ(3HA)(λ) and J(1)/J(NO2), the effective photodissociation quantum yield was calculated to be Φ(3HA) = 0.25 ± 0.06. The rate coefficient for the reaction with OH radicals was measured by the relative rate method with three reference compounds and was determined to be k(2) = (6.9 ± 0.9) × 10(-11) cm(3) molecule(-1) s(-1). The rate coefficient for the reaction with ozone was measured by an absolute method and was determined to be k(3) = (3.5 ± 0.2) × 10(-17) cm(3) molecule(-1) s(-1). Using the obtained rate coefficients, the daytime atmospheric lifetime of 3HA was estimated.     

溶液中甲醇和二氯亚砜的化学反应

用B3LYP方法和SCIPCM模型(模拟溶剂效应)研究了甲醇和二氯亚砜在两种非极性(ε<15)和两种极性(ε>15)溶剂中的反应(最终产物为氯代甲烷和二氧化硫). 反应过程由反应(1)和反应(2)组成, CH3OS(O)Cl是反应(1)的主要产物和反应(2)的反应物. 反应(2)有“前面取代”(经过渡态TS3f)和“背后取代”(先经CH3OS(O)Cl的电离, 再经过渡态TS3b)两种机理. 计算表明, 在气相和四种溶剂中反应(1)和(2)都是放热反应, 反应(1)具有相同的反应途径(经过渡态→中间体→过渡态), 溶剂的极性对反应(2)有很大的影响. 在气相和非极性溶剂中, TS3f的能量比(CH3OSO++Cl-)离子对(中间体IM2)的能量低, 反应(2)应为前面取代机理; 在极性溶剂中, IM2和TS3b的能量都比TS3f低, 反应(2)应为背后取代机理.     

两种新型丁二炔衍生物的合成

以3,5-二溴-1-｛3-（十二烷氧基）-2-［（十二烷氧基）甲基］丙氧基｝苯和2-甲基-3-丁炔-2-醇为原料,经选择性Sonogashira偶联反应,Sonogashira偶联反应和去硅保护基反应制得中间体--3-乙炔基-5-（3-甲基-3-羟基)-丁炔基-1-（3-十二烷氧基）-2-｛［（十二烷氧基）甲基］丙氧基｝苯（6）; 6经改良的Glaser偶联反应(CuI为催化剂,Et₃N为溶剂)合成了一个新型的丁二炔衍生物（1）。 6与2,2′-［（2,5-二碘-1,4-亚苯基）双（氧基）］双（四氢-2H-吡喃）经Sonogashira偶联,脱 THP保护基和改良的Glaser偶联反应合成了一个新型的丁二炔衍生物（2）。中间体,1和2的结构经¹H NMR, ¹³C NMR和MALDI-TOF-MS表征。     

钯(Ⅱ)催化CO/乙烯交替共聚反应机理反应状态下钯/膦配位结构的原位^3^1P NMR研究

应用加温加压原位核磁技术, 考察了不同配比的钯/膦催化剂在共聚反应条件下(C2H4/CO=1:1, 2.0MPa)的^3^1P NMR谱。实验表明, 在C2H4/CO共聚反应条件下, DPPP(1, 3-双二苯基膦丙烷)与Pd(OAc)2生成比较稳定的六元环螯合物,没有发现游离DPPP的^3^1P NMR信号。当反应温度高于100℃时, 螯合物即开始分解; 反应温度高于260℃时, 螯合物完全分解。DPPP/Pd(OAc)2=1时, 在反应条件下生成有活性的螯合物(DPPP)Pd(OCOCF3)2; DPPP/Pd(OAc)2>=2时, 在反应条件下生成无活性螯合物(DPPP)2Pd(OCOCF3)2。     

Reactions of 1-hydroxy-1-methylethyl radicals with NO2-: time-resolved electron spin resonance

The reaction of the alpha-hydroxyalkyl radical of 2-propanol (1-hydroxy-1-methylethyl radical) with nitrite ions was characterized. A product of the reaction was assigned as the adduct nitro radical anion, [HO-C(CH(3))(2)NO(2)](*-). This radical was identified using time-resolved electron spin resonance (TRESR). The radical's magnetic parameters, the nitrogen hyperfine coupling constant (a(N) = 26.39 G), and its g-factor (2.0052) were the same as those of the nitro radical anion previously discovered in (*)OH spin-trapping experiments with the aci-anion of (CH(3))(2)CHNO(2). Production of [HO-C(CH(3))(2)NO(2)](*-) was determined to be 38% +/- 4% of the reaction of (CH(3))(2)C(*)-OH with nitrite. The reason why this fraction was less than 100% was rationalized by invoking the competitive addition at oxygen, which forms [HO-C(CH(3))(2)ONO](*-), followed by a rapid loss of (*)NO. Furthermore, by taking this mechanism into account, the bimolecular rate constant for the total reaction of (CH(3))(2)C(*)-OH with nitrite at reaction pH 7 was determined to be 1.6 x 10(6) M(-1) s(-1), using both decay traces of (CH(3))(2)C(*)-OH and growth traces of [HO-C(CH(3))(2)NO(2)](*-). This correspondence further confirms the nature of the reaction. The reaction mechanism is discussed with guidance by computations using density functional theory.     

Boxes, helicates, and coordination polymers: a structural and magnetochemical investigation of the diverse coordination chemistry of simple pyridine-alcohol ligands

A structurally diverse array of polynuclear complexes has been identified and structurally characterized from the reaction of 6-methylpyridine-2-methanol (1) with a range of cobalt(II) salts under a variety of reaction conditions. A tetranuclear cubane, [Co4(1-H)4Cl4(H2O)3(CH3OH)], was isolated from the reaction of 1 with CoCl2.6H2O and NaOH in MeOH, and a tetranuclear double cubane, [Co4(1-H)6(NO3)2], was isolated from the reaction of 1 with Co(NO3)2.6H2O and NEt3 in MeOH. A bowl-shaped trinuclear complex, [Co3(1-H)3Cl3(dmso)], which features a triply bridging dmso ligand, assembled upon mixing 1 and CoCl2.6H2O in dmso. A 1-D coordination polymer, [Co(1)2(SO4)](infinity), where the sulfate ligands bridge "[Co(1)2]" units in a mu2:eta1 fashion to build up the polymer structure, was isolated from the reaction of 1 with CoSO4.7H2O. The reaction of the structurally related ligand 8-hydroxyquinaldine (2) with a mixture of CoCl2.6H2O and Co(OAc)2.4H2O lead to the formation of the tetranuclear double cubane, [Co4(2-H)6Cl2]. Temperature-dependent magnetic measurements have also been performed for these five complexes along with the hydrogen-bonded helicate [Co2(1)2(1-H)2]. The hydrogen bonds of the helicate mediate antiferromagnetic interactions between the cobalt(II) centers (J = -3.18(9) cm(-1), g = 2.25(2)). The sulfate bridging ligands of [Co(1)2(SO4)](infinity) are poor mediators of magnetic exchange. The Co(II) centers in the double-cubane complexes [Co4(1-H)6(NO3)2] and [Co4(2-H)6Cl2] are strongly antiferromagnetically coupled to each other at low temperature to give an S = 0 ground state. [Co4(1-H)4Cl4(H2O)3(MeOH)] exhibits rather complicated magnetic behavior; however, we did not observe any evidence for single-molecule magnetism as was seen for structurally related complexes.     

Preparation of 1-Trifluoroethyl-4-methoxy-5-chloropyridazin-6-one: Methyl Shift of 4-Methoxy-5-chloropyridazin-6-one

N1-Trifluoroethyl-4-methoxy-5-chloro-3-pyridazone (4) was synthesized by the substitution reaction of 4methoxy-5-chloro-3-pyridazone (1) with trifluoroethyl trifluoromethanesulfonate (A) at basic condition. In the most of reaction conditions, N1-methyl-4-methoxy-5-chloro-3-pyridazone (2) was obtained as a major by-product, which means that the methyl group in the 4-methoxy shifted to N-1 position inter-molecularly aided by A or trifluoroethyl methanesulfonate (B). We obtained N1-methyl-4-trifluoro-ethoxy-5-chloro-3-pyridazone (3) in the reaction of 1 with B at higher temperature in different solvents with different yield (Table 1 ), which mechanism was shown in Figure 1. When we tried to synthesize 4 in the reaction of 1 with trifluoroethyl toluenesulfonate under basic condition, 6 was obtained (Figure 2). All the detailed mechanisms are undergoing investigated.     

Binuclear cyclometalated organoplatinum complexes containing 1,1'-bis(diphenylphosphino)ferrocene as spacer ligand: kinetics and mechanism of MeI oxidative addition

The binuclear complex [Pt2Me2(ppy)2(mu-dppf)], 1, in which ppy = deprotonated 2-phenylpyridyl and dppf = 1,1'-bis(diphenylphosphino)ferrocene, was synthesized by the reaction of [PtMe(SMe2)(ppy)] with 0.5 equiv of dppf at room temperature. In this reaction when 1 equiv of dppf was used, the dppf chelating complex 2, [PtMe(dppf)(ppy-kappa1C)], was obtained. The reaction of Pt(II)-Pt(II) complex 1 with excess MeI gave the Pt(IV)-Pt(IV) complex [Pt2I2Me4(ppy)2(mu-dppf)], 3. When the reaction was performed with 1 equiv of MeI, a mixture containing unreacted complex 1, a mixed-valence Pt(II)-Pt(IV) complex [PtMe(ppy)(mu-dppf)PtIMe2(ppy)], 4, and complex 3 was obtained. In a comparative study, the reaction of [PtMe(SMe2)(ppy)] with 1 equiv of monodentate phosphine PPh3 gave [PtMe(ppy)(PPh3)], A. MeI was reacted with A to give the platinum(IV) complex [PtMe2I(ppy)(PPh3)], C. All the complexes were fully characterized using multinuclear (1H, 31P, 13C, and 195Pt) NMR spectroscopy, and complex 2 was further identified by single crystal X-ray structure determination. The reaction of binuclear Pt(II)-Pt(II) complex 1 with excess MeI was monitored by low temperature 31P NMR spectroscopy and further by 1H NMR spectroscopy, and the kinetics of the reaction was studied by UV-vis spectroscopy. On the basis of the data, a mechanism has been suggested for the reaction which overall involved stepwise oxidative addition of MeI to the two Pt(II) centers. In this suggested mechanism, the reaction proceeded through a number of Pt(II)-Pt(IV) and Pt(IV)-Pt(IV) intermediates. Although MeI in each step was trans oxidatively added to one of the Pt(II) centers, further trans to cis isomerizations of Me and I groups were also identified. A comparative kinetic study of the reaction of monomeric platinum(II) complex A with MeI was also performed. The rate of reaction of MeI with complex 1 was some 3.5 times faster than that with complex A, indicating that dppf in the complex 1, as compared with PPh 3 in the complex A, has significantly enhanced the electron richness of the platinum centers.     

Catalytic synthesis of tricyclic quinoline derivatives from the regioselective hydroamination and C-H bond activation reaction of benzocyclic amines and alkynes

The cationic ruthenium-hydride complex [(PCy3)2(CO)(CH3CN)2RuH]+BF4- (1) was found to be an effective catalyst for the regioselective coupling reaction of benzocyclic amines and terminal alkynes to form the tricyclic quinoline derivatives. The scope of the reaction was explored by using the catalytic system Ru3(CO)12/NH4PF6. The catalytically active cationic ruthenium-acetylide complex [(PCy3)2(CO)(CH3CN)2RuCCPh]+BF4- was isolated from the reaction of 1 with phenylacetylene.     

Synthesis and reactions of 3-carboxytropolone. Conversion to heterocycle-fused troponoid compounds

The haloform reaction of 3-acetyltropolone ( 1 ) afforded 3-carboxytropolone ( 2 ) which was treated with diazomethane to give 2-methoxy-3-methoxycarbonyltropone (3a) and 2-methoxy-7-methoxycarbonyltropone (3b). The tropolone 2 reacted with hydrazine to afford 2-hydrazino-3-hydrazinocarbonyltropone ( 10 ) or 2-hydrazinotropone ( 11 ), depending on the reaction time. The reaction of 2 with phenylhydrazine produced 3-hydroxy-1-phenyl-1,8-dihydrocycloheptapyrazol-8-one (14). The treatment of 2-methoxy-3-methoxycarbonyltropone (3a) with hydrazine or phenylhydrazine gave cyclization products 12 and 15 , respectively. The reaction of 2-methoxy-7-methoxycarbonyltropone (3b) with hydrazine, phenylhydrazine, or methylhydrazine gave 2-hydrazino- ( 13 ), 2-(2-phenylhydrazino)- ( 16 ), and 2-(2-methylhydrazino)-7-methoxycarbonyltropone ( 17 ), respectively.     

蒙脱土负载碘催化合成双吲哚甲烷衍生物

以蒙脱土负载碘(MMT/I2)作催化剂,醛(1a~1g)与吲哚(2)反应合成双吲哚甲烷衍生物(3a~3g),其结构经1H NMR和IR确证。以3a的合成为例,研究了催化剂、溶剂、反应时间、温度和物料比r[n(1)∶n(2)]对3产率的影响。结果表明:在最佳合成条件(2 1 mmol,r=1.1∶2.0,10 mol%MMT/I2,乙腈1 m L,于25℃反应5min)下,3a~3g产率67.9%~96.2%。MMT/I2循环使用3次,3a产率78.6%。     

Assembly of a heterobinuclear 2-D network: a rare example of endo- and exocyclic coordination of Pd(II)/Ag(I) in a single macrocycle

The S3O2 macrocycle L1 was synthesized by a dithiol-dihalide coupling reaction under high-dilution conditions. The reaction of L1 with K2PdCl4 afforded an exocoordinated complex 1, [cis-Cl2Pd(L1)], which can then be manipulated to provide a heterobinuclear complex 3, {[Pd(L1)Ag(NO3)(2.5)](NO3)(0.5)}n, utilizing endocyclic Pd(II) and exocyclic Ag(I) in a single macrocycle through a successive reaction with AgNO3. The network of 3 contains a unique honeycomb-like 2-D sheet made up of the repeating unit [Ag6(NO3)6].     

(6R,7R)-7-氨基-3-[2-(4-甲基-5-噻唑)乙烯基]-8-氧代-5-硫-1-氮杂双环[4.2.0]辛-2-烯-2-羧酸的合成

以1-磺丁基-3-甲基咪唑硫酸氢盐离子液体(b)为反应介质,7-氨基头孢烷酸(7-ACA,2)为原料,与4-甲基-5-甲酰基噻唑经缩合反应制得(6R,7R)-7-氨基-3-[2-(4-甲基-5-噻唑)乙烯基]-8-氧代-5-硫-1-氮杂双环[4.2.0]辛-2-烯-2-羧酸(7-ATCA,1),其结构经1H NMR,13C NMR和IR表征。考察了离子液体及其用量,原料摩尔比r[n(4-甲基-5-甲酰基噻唑)∶n(2)],反应温度和反应时间对1收率的影响。在最佳反应条件[b为反应介质,b用量为20 m L,r=1.3,于65℃反应5 h]下,1收率可达90%以上。     

Quantum-chemical study on the catalytic activity of TinRumO2(1 1 0) surfaces on chlorine evolution

Based on the generalized gradient approximation (GGA), Perdew-Wang-91 (PW91) combined with a periodic slab model has been applied to study the catalytic activity of chlorine evolution on TinRumO2(1 1 0) surface. Metal oxide model TinRumO2 has been established with pure TiO2 and RuO2 on the basis set of Double Numerical plus polarization (DNP), in which the proportion of n:m was 3:1, 1:1, or 1:3. Analysis on the reaction activity in the electrochemical reaction and the electrochemical desorption reaction was based on Frontiermolecular orbital theory. The results show that the TinRumO2 with a ratio of Ti:Ru at 3:1 is best facilitates the electrochemical reaction and electrochemical desorption reaction to produce M-Clads intermediate and precipitate Cl2. In addition, the adsorption energy of Cl on the surface of Ti3Ru1O2 possesses the minimum value of 2.514 eV, and thus electrochemical desorption reaction could occur most easily.     

Structural diversity of silver(I) 4,6-dipyridyl-2-aminopyrimidine complexes: effect of counteranions and ligand isomerism

Using two ligands, 4,6-bis(2-pyridyl)-2-aminopyrimidine (L1) with two N,N'-chelating sites and 4-(2-pyridyl)-6-(4-pyridyl)-2-aminopyrimidine (L2) (as the isomer of L1) containing one chelating site and one bridging unit, a series of novel Ag(I) complexes varying from zero- to two-dimensions have been prepared and their crystal structures determined via single-crystal X-ray diffraction. The two ligands are employed for the first time in coordination chemistry. The structures of compounds 1-3 are directed by the counteranions adopted in the reaction system: The reaction of L1 with AgNO3 yielded a dimer [Ag2L12](NO3)2 (1). The reaction of L1 with AgCF3SO3 led to a one-dimension "V-shaped" chain {[AgL1](CF3SO3)}n (2). When AgSCN was used, a one-dimension ladder {[Ag2L1(SCN)2].H2O}n (3) was obtained. While ligand L2 reacted with AgNO3, a two-dimension {[Ag2(L2)2](NO3)2.H2O}n (4) was prepared with the help of an argentophilic interaction. Compounds 1-4 display room-temperature photoluminescence.     

5-(4-叔丁氧基羰基哌嗪基)苯并呋喃-2-甲酸乙酯的合成

5-溴苯并呋喃-2-甲酸乙酯与4-叔丁氧基羰基哌嗪进行Buchwald-Hartwig偶联反应,若催化剂是Pd(OAc)2/BINAP,碱是Cs2CO3,则产物主要是5-(4-叔丁氧基羰基哌嗪基)苯并呋喃-2-甲酸乙酯,转化率达70%;若催化剂是Pd(dba)2/P(t-Bu)3,碱是叔丁醇钾,则产物中几乎没有5-(4-叔丁氧基羰基哌嗪基)苯并呋喃-2-甲酸乙酯.文中讨论了影响这个Buchwald-Hartwig偶联反应的因素.