碳苷研究XXVI:异黑豆素类似物的合成

本文首次报道了异黑豆素类似物, 6-非环糖基-4',7一二羟基黄酮的合成, 以2,4-二羟基苯甲酸为原料, 溴化和脱羧后以苄基作为羟基保护基, 通过Grignarcl反应获得具有各种不同侧链的中间体7,7氢解脱除苄基再用Fries重排或Frieclel-Crafts反应得到了C-Z酰化产物, 接着用碱缩合生成查尔酮, 经I2/H2SO4/DM SO氧化环合得到目标产物。     

碳苷研究——ⅩⅩⅥ.异黑豆素类似物的合成

本文首次报道了异黑豆素类似物,6-非环糖基-4′,7-二羟基黄酮的合成。以2,4-二羟基苯甲酸为原料,溴化和脱羧后以苄基作为羟基保护基,通过Grignard反应获得具有各种不同侧链的中间体7,7氢解脱除苄基再用Fries重排或Friedel-Crafts反应得到了C-乙酰化产物,接着用碱缩合生成查尔酮,经I_2/H_2SO_4/DMSO氧化环合得到目标产物1、2、3。     

碳苷研究 XXVII. 黑豆素非环类似物的合成

本文报道天然黄酮碳苷黑豆素非环类似物的合成, 以2,4-二羟基苯乙酮为原料, 经酚羟基的单苄基化、Claisen重排、醇醛缩合、I2/DMSO/浓度H2SO4关环五步反应得到黄酮; 用Claisen重排, 分别在黄酮环生成之前和生成之后引入8-位取代基侧链, 收率国产高。修饰8-位烯丙基侧链, 得到了六个黑豆素类似物, 共中8的7-位为游离羟基。     

碳苷研究 XXVII. 黑豆素非环类似物的合成

本文报道天然黄酮碳苷黑豆素非环类似物的合成, 以2,4-二羟基苯乙酮为原料, 经酚羟基的单苄基化、Claisen重排、醇醛缩合、I2/DMSO/浓度H2SO4关环五步反应得到黄酮; 用Claisen重排, 分别在黄酮环生成之前和生成之后引入8-位取代基侧链, 收率国产高。修饰8-位烯丙基侧链, 得到了六个黑豆素类似物, 共中8的7-位为游离羟基。     

1-氨基-2-(2'-甲基-4'-丙酸甲酯)苯氧基-4-羟基蒽醌的合成

邻甲苯酚与丙烯腈经Friedel-Crafts反应得到了2-甲基-4-β-氰基乙基苯酚,其与1-氨基-2-溴-4-羟基蒽醌经亲核取代形成的产物经水解、酯化得到目标化合物。给出了该化合物及其中间体的质谱、核磁共振氢谱、元素分析、可见光谱及熔点等数据。     

异单叶大黄素及其类似结构茋类化合物的合成方法

发展了一种异单叶大黄素及其类似结构的茋类化合物的合成方法.以3,5-二羟基苯甲酸为起始原料,通过苄基保护酚羟基,Wittig-Horner反应构建反式二苯乙烯结构产物,在钯碳/甲酸铵条件下,以较高收率脱苄基得到异单叶大黄素,总收率高达48%.并将该催化体系成功地应用于一系列羟基茋类化合物的合成,取得良好的效果.各步反应收率高,条件温和,所用试剂成本低、毒性小,操作简单、安全,适合较大量生产.为羟基茋类化合物的大批量合成提供了简便的途径.     

2-芳酰氨基-5-苄基-1,3,4-噻二唑上亚甲基与4-二甲氨基苯甲醛加成反应

本文报道了2-芳酰氨基-5-苄基-1,3,4-噻二唑(1a～l)与4-二甲氨基甲醛在EtONa/EtOH体系中反应得到12种新的2-芳酰氨基-5-[1'-苯基-2'-羟基(4'-二甲氨基苯乙基)]-1,3,4-噻二唑(2a～l) .     

(4-苄氧基苄基)-2,3-二-O-苄基-β-D-吡喃葡萄糖苷的合成

为合成酚酸取代的葡萄糖苷类天然产物,以全乙酰溴代葡萄糖为起始物,与4-苄氧基苄醇反应成苷,脱乙酰基后,选择性地在葡萄糖4,6-位形成亚苄基,2,3-位羟基用苄基保护,脱去亚苄基得到裸露葡萄糖4,6-位羟基的化合物(4-苄氧基苄基)-2,3-二-O-苄基-β-D-吡喃葡萄糖苷(7),该化合物可作为合成4,6-位选择性取代的葡萄糖衍生物的有效中间体。     

3-羟基异恶唑的O-和N-酰化及其区域选择性研究 Ⅱ.3-羟基-5-甲基异恶唑O-和N-酰化产物的选择性合成

本文研究了不同反应条件下3-羟基-5-甲基异恶唑(1)与3-甲基-2- 对氯苯基丁酰氯(2a)的反应,提出了区域选择性合成O-和N-酰化产物的方法.在三乙胺存在下,乙腈为溶剂,1和2a～2e反应得到含量为88～96%的O-酰化产物3a～3e,而若将1 转化为相应的异恶唑硅醚4,再与2a～2i反应,则得到含量为86～97%的N-酰化产物5a～5i.试验表明,在DMAP催化下,3a和5a可发生O-/N-酰基转移反应     

SO42-/ZrO2催化氯化苄与苯烷基化反应的气相色谱-质谱法分析

采用气相色谱-质谱法(GC/MS)对SO42-/ZrO2固体超强酸催化氯化苄与苯烷基化反应产物的组成与结构进行了分析,并对SO42-/ZrO2催化的选择性进行了初步探讨。结果表明:SO42-/ZrO2固体超强酸对氯化苄与苯的烷基化反应具有良好的催化活性,反应产物主要为二苯甲烷、苄基二苯甲烷与氯甲基二苯甲烷等7种苄基化物。SO42-/ZrO2固体超强酸催化的产物选择性与经典Lew is酸催化特征基本一致。     

多氟芳烃的亲核反应II: 一氯五氟苯的亲核环化

本文报道一氯五氟苯与双官能团亲核试剂反应制备环化产物的研究结果, 发现应用NaH-DMF体系制备醇钠, 有利于亲核反应的顺利进行, 环化产物产率有较大幅度提高.     

异-α-姜黄烯及其衍生物的合成

姜科姜黄属是一个重要的药用植物群其根茎和块根分别称为姜黄和郁金。中医中药认为, 郁金具有行气, 纠瘀和通经等功效。动物药理试验表明, 姜科植物温郁金具有抗生育活性, 而其挥发油主要含有姜烯、α-姜黄烯和异-α-姜黄烯等倍半萜类化合物。本文合成了温郁金挥发油的另一个成分异-α-姜黄烯和其衍生物2-甲基-6-对甲苯基-2-庚醇、脱氢异-α-姜黄烯和2-甲基-6-对甲苯基-5-庚烯-2-醇。它们的化学结构得到确证。     

CH3NO2+X(X=H,OH, CH3, CH2[^3B1], O[^3P])→CH2NO2+XH吸氢反应过渡态 结 构和反应位垒的DFT计算研究

采用DFT(B3LYP)方法,分别在6-311g(d,p),6-311++g(d,p)和自洽相关基组cc-pVIZ水平上优化了基态硝基甲烷和自由基H,OH,CH3,CH2[^3B1]以及O[^3P]等发生吸氢反应时的过渡态结构,并计算了反应的位垒。研究表明,对同一反应,不同基组下优化得到的过渡态几何结构基本一致;反应位垒数值的大小也基本接近,经校正,硝基甲烷同自由基反应位垒的理论计算值同实验结果基本吻合。     

冠醚菁染料的研究V.苯并咪唑冠醚衍生物的合成

Crown ether cyanine dye precursors I (R = Et, CH2CH2OH; X = I, Cl, (CH2)3SO3) were prepared and characterized by elemental anal., NMR, and IR spectroscopy. The unquaternized I was prepared by cyclization of 4,5-dinitrobenzo-15-crown-5 in the presence of AcOH followed by ethylation in the presence of KOH.     

β-羟基丙醛基态与激发态氢迁移反应的从头算研究

本文用从头算RHF和UHF方法在3-21G基组上研究了β-羟基丙醛基态和激发态分解为甲醛和乙烯醇的反应机理。优化得到了各反应途径的过渡态和中间体, 其结果为: 基态β-羟基丙醛经过一个六元环过渡态和一个氢键中间体形成产物, 反应属于氢迁移和断键的协同过程; 激发三态β-羟基丙醛的分解途径首先经过一个氢迁移六元环过渡态形成双自由基中间体, 然后该中间体的分解包括两条相互竞争的途径, 它们各自经过一个断碳碳键的过渡态和一个氢键激-基态配合物中间体而形成两类产物, 一类为甲醛的基态和乙烯醇的激发态, 另一类为甲醛的激发态和乙烯醇的基态。激发态反应的两条通道均属于先氢迁移后断键分解的分步过程, 且反应的第二步为速控步骤。计算结果表明, 激发态反应活化位垒都比基态的低。     

1-丙醇和2-丙醇的真空紫外光电离质谱研究

研究了在9.84 – 11.80 eV光子能量范围内1-丙醇和2-丙醇的光电离和离解光电离，测量了1-丙醇离解电离产生的碎片离子CH3CH2CH2OH+, CH3CH2CHOH+, CH2CH2OH+, CH3CH2CH2+, CH3CH=CH2+和CH2OH+及2-丙醇离解电离产生的碎片离子CH3CH(OH)CH3+, CH3C(OH)CH3+, CH3CHOH+, CH2=CHOH+, CH3CHCH3+和CH3CH=CH2+的光电离效率谱，得到了这些离子的出现势。结合从头算理论计算，给出了1-丙醇的碎片离子CH3CH2CHOH+, CH2CH2OH+, CH3CH2CH2+, CH3CH=CH2+, CH2OH+和2-丙醇的碎片离子CH3C(OH)CH3+, CH3CHOH+, CH2=CHOH+, CH3CHCH3+, CH3CH=CH2+等的解离通道和解离能。理论计算结果与实验结果符合得很好。     

二取双恶唑啉衍生物的合成及其在不对称环丙烷化反应中的应用

通过双亚氨酸盐酸盐与手性胺醇反应简便地合成了二取代双恶唑啉衍生物, 并将其与铜配位运用于重氮醋酸酯对烯烃的不对称环丙化反应, 不对称诱导反应光学产物收率最高达95%d.e.     

13C, 18O, and D fractionation effects in the reactions of CH3OH isotopologues with Cl and OH radicals

A relative rate experiment is carried out for six isotopologues of methanol and their reactions with OH and Cl radicals. The reaction rates of CH2DOH, CHD2OH, CD3OH, (13)CH3OH, and CH3(18)OH with Cl and OH radicals are measured by long-path FTIR spectroscopy relative to CH3OH at 298 +/- 2 K and 1013 +/- 10 mbar. The OH source in the reaction chamber is photolysis of ozone to produce O((1)D) in the presence of a large excess of molecular hydrogen: O((1)D) + H2 --> OH + H. Cl is produced by the photolysis of Cl2. The FTIR spectra are fitted using a nonlinear least-squares spectral fitting method with measured high-resolution infrared spectra as references. The relative reaction rates defined as alpha = k(light)/k(heavy) are determined to be: k(OH + CH3OH)/k(OH + (13)CH3OH) = 1.031 +/- 0.020, k(OH + CH3OH)/k(OH + CH3(18)OH) = 1.017 +/- 0.012, k(OH + CH3OH)/k(OH + CH2DOH) = 1.119 +/- 0.045, k(OH + CH3OH)/k(OH + CHD2OH) = 1.326 +/- 0.021 and k(OH + CH3OH)/k(OH + CD3OH) = 2.566 +/- 0.042, k(Cl + CH3OH)/k(Cl + (13)CH3OH) = 1.055 +/- 0.016, k(Cl + CH3OH)/k(Cl + CH3(18)OH) = 1.025 +/- 0.022, k(Cl + CH3OH)/k(Cl + CH2DOH) = 1.162 +/- 0.022 and k(Cl + CH3OH)/k(Cl + CHD2OH) = 1.536 +/- 0.060, and k(Cl + CH3OH)/k(Cl + CD3OH) = 3.011 +/- 0.059. The errors represent 2sigma from the statistical analyses and do not include possible systematic errors. Ground-state potential energy hypersurfaces of the reactions were investigated in quantum chemistry calculations at the CCSD(T) level of theory with an extrapolated basis set. The (2)H, (13)C, and (18)O kinetic isotope effects of the OH and Cl reactions with CH3OH were further investigated using canonical variational transition state theory with small curvature tunneling and compared to experimental measurements as well as to those observed in CH4 and several other substituted methane species.     

Experimental and computational investigation of gas-phase reaction of chlorine with n-propanol: observation of chloropropanol conformational isomerization at room temperature

FTIR smog chamber techniques were used to measure k(Cl+n-C3H7OH) = (1.74 +/- 0.15) x 10-10 and k(Cl+CH2ClCH2CH2OH) = (7.54 +/- 0.73) x 10-11 cm3 molecule-1 s-1 in 700 Torr of N2 at 296 K. The reaction of Cl with n-C3H7OH gives CH3CH2CHOH, CH3CHCH2OH, and CH2CH2CH2OH radicals in yields of 60 +/- 5, 25 +/- 8, and 15 +/- 3%, respectively. Neither CH3CH2CHClOH nor CH3CHClCH2OH is available commercially, and infrared spectra for the three chlorides CH3CH2CHClOH, CH3CHClCH2OH, and CH2ClCH2CH2OH were calibrated experimentally. MP2/6-31G(d,p) calculations were used to corroborate the experimental vibrational assignments. Analysis reveals that each geometric isomer possesses several structurally and spectroscopically distinct conformers arising from intramolecular hydrogen bonding and, in the case of CH3CH2CHClOH, negative hyperconjugation. These conformers interchange slowly enough to be distinguished within the room-temperature vibrational spectrum. The experimentally observed vibrational spectra are well described by a Boltzmann-weighted superposition of the conformer spectra. As is typical of alpha-halogenated alcohols, CH3CH2CHClOH readily decomposes heterogeneously to propanal and HCl.     

CH3CH2+O(3P)反应机理的理论研究

The reaction for CH3CH2+O(3P) was studied by ab initio method. The geometries of the reactants, intermediates, transition states and products were optimized at MP2/6-311+G(d,p) level. The corresponding vibration frequencies were calculated at the same level. The single-point calculations for all the stationary points were carried out at the QCISD(T)/6-311+G(d,p) level using the MP2/6-311+G(d,p) optimized geometries. The results of the theoretical study indicate that the major products are the CH2O＋CH3, CH3CHO+H and CH2CH2+OH in the reaction. For the products CH2O＋CH3 and CH3CHO+H, the major production channels are A1: (R)→IM1→TS3→(A) and B1: (R)→IM1→TS4→(B), respectively. The majority of the products CH2CH2+OH are formed via the direct abstraction channels C1 and C2: (R)→TS1(TS2)→(C). In addition, the results suggest that the barrier heights to form the CO reaction channels are very high, so the CO is not a major product in the reaction.