Sequential nature of the exothermic reactions leading to the formation of flexible polyurethane foams

The exotherms of the reactions leading to the formation of polyurethane foams were measured. The inflection points of the exotherm curves were made evident by continuous differentiation with respect to time. The position and magnitude of the inflection points demonstrated the sequential nature of the reactions. The effects of the functionality of the polyol, the concentrations of the tin and amine catalysts, and the silicone surfactant are discussed.     

Characterization of irreversible kinase inhibitors by directly detecting covalent bond formation: a tool for dissecting kinase drug resistance

Targeting protein kinases in cancer therapy with irreversible small-molecule inhibitors is moving to the forefront of kinase-inhibitor research and is thought to be an effective means of overcoming mutation-associated drug resistance in epidermal growth factor receptor kinase (EGFR). We generated a detection technique that allows direct measurements of covalent bond formation without relying on kinase activity, thereby allowing the straightforward investigation of the influence of steric clashes on covalent inhibitors in different resistant kinase mutants. The obtained results are discussed together with structural biology and biochemical studies of catalytic activity in both wild-type and gatekeeper mutated kinase variants to draw conclusions about the impact of steric hindrance and increased catalytic activity in drug-resistant kinase variants.     

Arylation reactions: the photo-S(N)1 path via phenyl cation as an alternative to metal catalysis

Photo(sensitized) cleavage of benzenediazonium salts as well as, when an electron-donating substituent is present, of aryl chlorides, fluorides, mesylates, triflates, and phosphates leads to the corresponding phenyl cations in the triplet state. These otherwise unavailable intermediates add selectively to alkenes, alkynes, and (hetero)arenes, giving arylation products in a good yield. The reactions are photochemical alternatives of metal-catalyzed Heck and cross-coupling reactions and bear some mechanistic analogy with them.     

Carbon-carbon bond formation involving reactions of alkynes with group 9 metals (Ir, Rh, Co): preparation of conjugated olefins

Stable alkynyl complexes of iridium(III) (L(n)Ir-triple bond-R) that are prepared from the reactions of terminal alkynes readily undergo the intramolecular C-C bond-forming reactions between the alkynyl and adjacent hydrocarbyl ligands to yield conjugated olefins. These reactions are initiated by electrophiles (H(+), Me(+)) that attack the beta carbon of the alkynyl ligand to increase the electrophilicity of the alpha carbon of the alkynyl ligand. The C-C bond is then formed between the alpha carbons of the alkynyl and adjacent hydrocarbyl ligands.     

C-S bond formation in aromatic substrates using Mn(II)-promoted montmorillonite clays

Direct introduction of -SCH₃ groups into activated aromatic and hetero aromatic compounds has been achieved by reaction with dimethyldisulfide over a MnCl₂-promoted K-10 montmorillonite. Unlike ZnCl₂/K-10, the Mn- promoted clay appears to promote reaction by coordination of the aromatic substrate at the active site followed by attack of the disulfide at the activated aromatic. This revised version was published online in July 2006 with corrections to the Cover Date.     

X(S)N75加压式捏炼机转子密封环的改造

通过对X（S）N75加压式捏炼机转子端面密封结构的分析，找到了密封失效的主要原因。对新选择的静密封环材料进行试验与探讨，对影响密封的其它相关环节进行优化控制，从而延长了静密封环的使用时间，改善了密封效果，取得明显的经济和社会效益。     

Observations on the mechanism of alkali-silica reactions in concrete: Rhythmic reactions (liesegang ring formation)

Studies of reacted glass particles in concretes affected by deleterious alkali-silica reaction appear to show that the relatively slow diffusion of hydroxyl ions followed by comparatively fast reaction induces rhythmic reaction and periodic cracking analogous to Liesegang Ring formation. No evidence for sodium ion diffusion into the cement paste could be obtained by EPMA.     

Dynamic operating policies for periodic processes subject to equipment failures

The role of storage in buffering a process train from the effects of periodically reoccuring equipment failure is studied. The effects of deterministic and stochastic variations in the failure frequency and recovery time on the required size of intermediate storage are investigated. A dynamic operating policy is proposed to accommodate process variations in concern with the use of intermediate storage. Dynamic operation offers an increase in the average production rate of the process while using only modest levels of intermediate storage.     

Unusual iron-mediated C–N bond formation and synthesis of the Fe(III) complex of a polypyridine ligand with one carboxamide group

A high-spin iron(III) chloro complex [(PaPPy₃)Fe(Cl)](ClO₄) (1, where =N,N-bis(2-pyridylmethyl)amine-N-propyl-2-pyridine-2-carboxamide) has been synthesized via the “template effect” and structurally characterized. The template reaction leads to the formation of a new carbon–nitrogen bond from coupling of a primary alkyl chloride with a secondary amine.     

Shape selective solvent inclusion within the lattice of bis(N1,N1,N5,N5-tetrabenzyl-2,4-dithiobiureto)nickel(II)

The crystal structure of the stable toluene solvate of bis(N¹,N¹,N⁵,N⁵-tetrabenzyl-2,4-dithiobiureto)nickel(II) shows that the solvent molecules are held within lattice cavities of well-defined size and shape. Recrystallisation from a mixture of xylenes was found to yield selectively the p-xylene solvate.     

(1R,3S)-樟脑酸制备(1S,3R)-樟脑酸酐过程中构型翻转的研究

(1S,3R)-樟脑酸酐由(1R,3S)-樟脑酸制得并经过元素分析、红外光谱、比旋光度和X-射线单晶衍射表征。通过晶体结构和量子化学计算的结果对该化合物中两个手性碳原子同时发生构型翻转进行了讨论。(1S,3R)-樟脑酸酐的晶体学数据:正交晶系,空间群为P2(1)2(1)2(1),a=0 64872(15)nm,b=1 1190(3)nm,c=1 3010(3)nm,V=0 9444(4)nm3,Z=4,Dc=1 282Mg·m-3,Rint=0 0555,S=1 001,I>2σ(I)data:R1=0 0454,wR2=0 0927,alldata:R1=0 0588,wR2=0 0959。     

(S)-1-氯-3-甲基丁基硼酸-( )-蒎烷二醇酯的合成

考察了医药中间体(S)-1-氯-3-甲基丁基硼酸-(+)-蒎烷二醇酯的合成,由异丁基硼酸经酯化,同系化反应制得,总收率87.6%。用单因素法优化了工艺条件,酯化反应:正己烷中回流反应5 h,2-甲基丙基硼酸-(+)-蒎烷二醇酯收率为98.5%;同系化反应:n〔2-甲基丙基硼酸-(+)-蒎烷二醇酯〕∶n(LDA)∶n(ZnCl2)=1∶2∶1.7,-78℃反应4 h,(S)-1-氯-3-甲基丁基硼酸-(+)-蒎烷二醇酯收率89.0%。中间体和目标产物用GC/MS、1 HNMR等方法分析,确认了其结构。     

(S)-1-(1-苯基乙基)-4-哌啶酮的合成

该文以(S)-1-苯乙胺、丙烯酸甲酯为原料,经Michael加成,Dieckmann环合,脱羧,合成了(S)-1-(1-苯基乙基)-4-哌啶酮。并对所涉及的Michael加成反应的工艺参数进行了优化。当(S)-1-苯乙胺与丙烯酸甲酯的摩尔比为1∶2.5,40℃反应10h,收率为92.4%,总收率为89.3%。目标产物及中间体的结构经核磁共振波谱进行了表征。     

N，N－双（1－羟基－戊醛基）－5，5－二甲基海因的合成研究

利用５，５－二甲基海因与戊二醛的缩合反应合成标题化合物（１），该化合物是一种新型高效消毒剂。对其杀菌消毒能力进行了初步测试。     

S—N—[（1—乙基—2—吡咯烷基）甲基]—2—羟基—3—碘—6—甲氧基苯甲酰胺的合成

报道了苯甲酰胺衍生物Ｓ－Ｎ－〔（１－乙基－２－吡咯烷基）甲基］－２－羟基－３－碘－６－甲氧基苯甲酰胺（Ｓ－ＩＢＺＭ）的合成,产物经红外、核磁共振等测定,与结构相符。