Ni_(x)Cu_(y)-B_(24)N_(28)催化CO_(2)氧化C_(3)H_(8)速控步骤的反应机理研究北大核心CSCD

采用密度泛函理论(DFT)研究了C_(3)H_(8)和CO_(2)在Ni_(x)Cu_(y)-B_(24)N_(28)(x+y=4,x=1、2、3、4)表面吸附及速控步骤反应机理.计算了C_(3)H_(8)、CO_(2)和相应中间体在Ni_(x)Cu_(y)-B_(24)N_(28)表面的吸附能以及6条可能路径下的反应热和活化能.计算结果表明,C_(3)H_(8)和CO_(2)在Ni_(x)Cu_(y)-B_(24)N_(28)表面是物理吸附,C_(3)H_(8)+CO_(2)→CH_(3)CHCH_(3)+OCOH是最有利的路径,其在不同催化剂表面的活化能顺序是NiCu_(3)-B_(24)N_(28)(1.42 eV)、Ni_(2)Cu_(2)-B_(24)N_(28)(1.57 eV)、Ni_(3)Cu-B_(24)N_(28)(1.62 eV)、Ni_(4)-B_(24)N_(28)(1.75 eV).由此可知,在Ni_(x)Cu_(y)-B_(24)N_(28)催化CO_(2)氧化C_(3)H_(8)的体系中,Cu含量直接影响其催化活性,即NiCu_(3)-B_(24)N_(28)用于催化CO_(2)氧化C_(3)H_(8)有一定优势.     

核酸化学研究 Ⅲ.酵母丙氨酸转移核糖核酸TψC臂ApUpUpC、CpGpGpA和ApUpUpCp的合成

本文报道了带保护基的四核苷三磷酸(Bz)A_(bzp)~(bz)U_(bzp)U_(bzp)C_(Bz)~(bz),(9),(Bz)A_(bzp)~(bz)U_(bzp)C_(bzp)~(bz)U(Bz_2(15),C_(bzp)~(bz)G_(ibup)~(ac)G_(ibup)~(ac)A_((Bz)_2)~((bz)_2)(24)和四核苷酸(Bz)一A_(bzp)~(bz)U_(bzp)U_(bzp) Cv_(bzp)~(bz)(29)的合成。三个四核苷三磷酸均用相应的二核苷二磷酸和二核苷一磷酸,即化合物9由(Bz)A_(bzp)~(bz)U_(bzp)(4)和U_(bzp)C_((Bz)_2)~(bz)(8),化合物15由4和C_(bzp)~(bz)U(Bz)_2(14),化合物24由(McOTr)C_(bzp)~(bz)G_(ibup)~(ac)(19)和G_(ibup)~(ac)A_(Bz)_2~((bz)_2)(23)缩合而得。四核苷酸(Bz)A_(bzp)~(bz)U_(bzp)U_(bzp)C_(bzp)~(bz)(29)由化合物4和二核苷酸U_(bzp)~(bz)(28)缩合而成。四者均用二环己基碳二亚胺为缩合剂。化合物9、15、24和29在去保护基、纯化后分别得到纯的ApUpUpC(10)、ApUpCpU(16)、CpGpGpA(25)和ApUpUpCp(30)。在反应后处理条件和二乙基氯乙基纤维素柱层析条件下,对化合物G_p~(ac)、G_p~(ibu)、G_(acp)~(ac)、G_(ibup)~(ac)、G_(bzp)~(ac)和G_(ibup)~(ibu)上的酰基保护基的稳定性作了比较。     

《催化学报》第四届编辑委员会

顾问 (Advisors)蔡启瑞 (CAIQirui)闵恩泽 (MINEnze)彭少逸 (PENGShaoyi)胥诲熊 (XUHuixiong)BernardDELMON(Belg) GerhardERTL(Ger)MasaruICHIKAWA(Jpn)主编 (Editor in Chief)林励吾 (LINLiwu)副主编 (AssociateEditors in Chief)包信和 (BAOXinhe)高　滋 (GAOZi)寇　元 (KOUYuan)王国祯 (WANGGuozhen)编委 (Members)包信和 (BAOXinhe)陈庆龄 (CHENQingling) 陈诵英 (CHENSongying) 陈耀强 (CHENYaoqiang)陈　懿 (CHENYi)邓友全 (DENYouquan) 伏义路 (FUYilu)高　滋 (GAOZi)关乃佳 (GUANNaij…     

《催化学报》第四届编辑委员会

顾问 (Advisors)蔡启瑞 (CAIQirui)闵恩泽 (MINEnze)彭少逸 (PENGShaoyi)胥诲熊 (XUHuixiong)BernardDELMON(Belg) GerhardERTL(Ger)MasaruICHIKAWA(Jpn)主编 (Editor in Chief)林励吾 (LINLiwu)副主编 (AssociateEditors in Chief)包信和 (BAOXinhe)高　滋 (GAOZi)寇　元 (KOUYuan)王国祯 (WANGGuozhen)编委 (Members)包信和 (BAOXinhe)陈庆龄 (CHENQingling) 陈诵英 (CHENSongying) 陈耀强 (CHENYaoqiang)陈　懿 (CHENYi)邓友全 (DENYouquan) 伏义路 (FUYilu)高　滋 (GAOZi)关乃佳 (GUANNaij…     

《催化学报》第四届编辑委员会

顾问 (Advisors)蔡启瑞 (CAIQirui)闵恩泽 (MINEnze)彭少逸 (PENGShaoyi)胥诲熊 (XUHuixiong)BernardDELMON(Belg) GerhardERTL(Ger)MasaruICHIKAWA(Jpn)主编 (Editor in Chief)林励吾 (LINLiwu)副主编 (AssociateEditors in Chief)包信和 (BAOXinhe)高　滋 (GAOZi)寇　元 (KOUYuan)王国祯 (WANGGuozhen)编委 (Members)包信和 (BAOXinhe)陈庆龄 (CHENQingling) 陈诵英 (CHENSongying) 陈耀强 (CHENYaoqiang)陈　懿 (CHENYi)邓友全 (DENYouquan) 伏义路 (FUYilu)高　滋 (GAOZi)关乃佳 (GUANNaij…     

2007年催化学报第28卷作者索引

AABBASI Alireza(4)357ABDUL GHANIAbdul Aziz(12)1037AOUISSI Ahmed(12)1041安霞(8)681(9)766B白亮(11)1013白雪(11)953白雪峰(3)234白志鹏(12)1089包信和(2)180鲍晓军(4)364CC,ETI.NKAYAEngin(6)489蔡红丽(9)758蔡天锡(7)585蔡铁军(1)10蔡振钱(2)153曹洁明(1)17曹勇(11)987岑亚青(9)811柴海芳(3)196常福祥(9)817常杰(8)687常涛(4)287(5)404晁然(6)501陈斌(1)3陈春城(12)1117陈锋(3)229陈华(11)975(12)1057陈会慧(6)501陈惠麟(11)934陈吉祥(5)435(6)498陈建刚(7)596陈金春(2)131陈金伟(8)725陈经广(8)676陈静(2)158陈静(1…     

2005年 催化学报 第26卷 作者索引

A安立敦(11)1022安欣(9)729B白吉玲(8)688白静宇(1)25白亮(4)340(5)371(7)614(8)693(8)701(9)791(10)859包信和(5)412(5)423(8)660(9)769(10)832(12)1037C蔡敬民(11)977蔡天锡(5)403(8)628(9)734蔡伟民(3)189操小栋(2)148曹丹(3)248曹飞(6)513曹建秋(3)238曹洁明(10)847曹凯(11)1027曹勇(1)7(4)311(6)455曹喻霖(10)847岑沛霖(11)993柴永明(8)672常杰(7)614(8)693(8)701(9)731(10)859常欣(10)847陈柏龄(6)455陈标华(5)428陈东(11)987陈光文(9)809(9)824陈浩(4)311陈皓(11)1005陈红亮(12)1039陈华(1)4(12)1093陈会英(9)769陈吉祥(1)20陈继新…     

《催化学报》第四届编辑委员会

顾问(Advisors)蔡启瑞(CAI Qirui)闵恩泽(MI N Enze)彭少逸(PENG Shaoyi)胥诲熊(XU Huixiong)Bernard DELMON(Belg)Gerhard ERTL(Ger)Masaru ICHIKAWA(Jpn)主编(Editor-in-Chief)林励吾(LI N Li wu)副主编(Associate Editors-in-Chief)包信和(BAO Xinhe)高滋(GAO Zi)寇元(KOU Yuan)王国祯(WANG Guozhen)编委(Members)安立敦(AN Lidun)包信和(BAO Xinhe)陈庆龄(CHEN Qingling)陈诵英(CHENSongying)陈耀强(CHEN Yaoqiang)陈懿(CHEN Yi)邓友全(DENG Youquan)方佑龄(FANG Youling)伏义路(FU Yilu)…     

2006年催化学报第27卷作者索引

A艾刚(10)885安立敦(2)161安洋(10)875BBACHILLER-BAEZA Belen(2)109白荣献(2)103白赢(3)275包信和(1)65(2)166(5)381(6)474(9)827毕伟(10)911毕亚东(8)659C蔡伟杰(7)567蔡伟民(10)890蔡卫权(9)805蔡振钦(7)615曹光群(7)611曹雷(10)932曹梅娟(1)55(3)223曹维良(2)135曹卫强(10)     

Synthesis,structure, and catalytic activity of rare-earth metal amides with a neutral pyrrolyl-functionalized indolyl ligand

<正>1 Representation of complexes and selected bond distances and bond angles Figure S1 Structure of complex 4. Hydrogen atoms were omitted for clarity, ellipsoids set at the 30% probability level. Selected bond distances() and angles(°): Er(1)–Cl(1) 2.6180(18), Er(1)–N(1) 2.301(6), Er(1)–N(4) 2.232(6), Er(1)–N(5) 2.229(6), N(1)–Er(1)–Cl(1) 87.41(14), N(4)–Er(1)–Cl(1) 101.16(14), N(5)–Er(1)–Cl(1) 118.60(16), N(4)–Er(1)–N(1) 114.1(2), N(5)–Er(1)–N(1) 108.7(2), N(5)–Er(1)–N(4) 121.9(2).Figure S2 Structure of complex 5. Hydrogen atoms were omitted for clarity, ellipsoids set at the 30% probability level. Selected bond distances(o) and angles(°): Y(1)–Cl(1) 2.6212(12), Y(1)–N(1) 2.280(3), Y(1)–N(4) 2.214(3), Y(1)–N(5) 2.228(3), N(1)–Y(1)–Cl(1) 87.67(8), N(4)–Y(1)–Cl(1) 121.32(8), N(5)–Y(1)–Cl(1) 102.88(8), N(4)–Y(1)–N(1) 107.75(11), N(5)–Y(1)–N(1) 111.64(11), N(4)–Y(1)–N(5) 120.78(10).     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.