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烯烃基

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In chapter three, the activating agents of ytterbium have been examined. Barbier-type reaction promoted by ytterbium metal was examined. The experimental results shown that the yield of Barbier reaction of imines with allylic bromide promoted by ytterbium is higher than that of aldehydes and ketones with allylic bromide under the same reaction conditions. In this chapter, the reductive cleavage of Se-Se and S-S bond induced by ytterbium metal was also studied.

首先研究了金属镱的活化剂以及活化方法,接着考察了金属镱促进的Barbier反应及其在合成高烯丙基胺和高烯丙基醇中的应用,以及影响该反应的主要因素;究了金属镱促进的二硫醚和二硒醚的S—S键和Se—Se键的还原断裂,继而与氯代烃,胺基甲酰氯反应生成相应的硫醚,硒醚,胺基甲酸硫代酯和硒代酯。

Master the Keto-Enol tautomerism; reactions of enols:α-H substitution reactions;α-halogenation of aldehydes and ketones;α-bromination of carboxylic acids; acidity ofα-H atoms: enolate ion formation; reactivity of enolate ions; alkylation of enolate ions; mechanism of carbonyl condensation reactions;condensations of aldehydes and ketones: the Aldol reaction; dehydration of Aldol products; the Claisen condensation reaction; the Michael addition.

熟练掌握酮式-烯醇式互变异构;烯醇的反应:α-H的活性;醛酮的α卤代反应;羧酸的α-溴代反应;α-H的酸性:烯醇负离子的形成;烯醇负离子的反应;烯醇负离子的烃基化;羰基化合物的缩合反应机理;醛酮的缩合反应-Aldol缩合;Aldol缩合产物的脱水反应; Cleisen 酯缩合反应;麦克尔加成反应。

Also useful are oil-soluble copper dithiocarbamates of the general formula Rc Rd z Cu, where z is 1 or 2, and Rc and Rd are the same or different hydrocarbyl radicals containing from 1 to 18, and preferably 2 to 12, carbon atoms, and including radicals such, for example, as alkyl, alkenyl, aryl, aralkyl, alkaryl and cycloaliphatic radicals.

化学通式为Rc Rd z Cu的油溶性二硫代氨基甲酸铜也适用,式中,z为1或2,Rc和Rd是含1~18(以2~12为宜)个碳原子的相同或不同的烃基,这类烃基的实例包括烷基、烯基、芳基、芳烷基、烷芳基和脂环基。

The speed of electrophilic addition reaction of Alkene is inferenced greatly by the electron-withdrawing group or electron-releasing group on C=C of Alkene And the main addition product is decided by stability of carbonium ion.

烯烃C=C上连有供电子基和吸电子基时,对于烯烃亲电加成反应速度的影响是很大的。加成产物是由碳正离子中间体的稳定性来决定。

The effect of zeolites ion-exchanged by transition metals on thermal catalytic cracking reaction is studied. The product distributions of the cracking reactions catalyzed by theβor ZSM-5 zeolites exchanged with transition metals are different from that catalyzed by corresponding Hzeolites, which means the mechanism of cracking reactions has varied. Group Ⅷ metals Fe, Co, Ni and Cu, Zn are shown to be of strong catalytic activity of oxidative dehydrogenation, while Ti and Cr are not of oxidative activity. Catalyzed by zeolites or catalyst containing Ag, conversion of thermal catalytic cracking reactions and the yield of ethylene increase while the yield of propylene does not decrease. Silver can not only promote the formation of carbonium ion, but also convert carbonium ion into free-radical via redox reaction. The weak adsorption of olefins on silver reduces the occurrence of hydrogen transfer and dehydrogenation. As a result, the yield of light olefins is favored by silver in the catalyst.

采用过渡金属交换的分子筛作为催化剂,进行催化热裂解制取乙烯的反应,研究发现,在β沸石分子筛和ZSM-5分子筛中引入过渡金属后,催化热裂解反应的产物分布与相应的氢型分子筛相比有了较大的变化,说明过渡金属的加入对于催化热裂解反应的机理具有影响,Ⅷ族金属如Fe、Co、Ni和第Ⅰ、Ⅱ副族Cu、Zn表现出较强的氧化脱氢活性,产物中氢气、焦炭的产率很高,Ti、Cr则未表现出氧化作用:分子筛及催化剂中引入银后,催化热裂解反应的转化率和乙烯的产率有了提高,丙烯产率没有很大的变化,说明银在催化热裂解反应中能够促进正碳离子的生成,又有可能通过氧化-还原作用部分改变反应机理,促进了自由基的生成,并且由于银对烯烃的吸附很弱,其氢转移反应和脱氢、加氢活性比较低,有利于烯烃产率的提高。

On the other hand, a method for the synthesis of-vinyl chalcogenides by the coupling of vinyl bromides with thiols or diphenyl diselenide using copper salts as catalysts in ionic liquids based on amino acids also has been described. The ionic liquids play multiple roles in the reaction: they act as solvent, base, and excellent promoter for the copper-catalyzed coupling reactions.

在新型的氨基酸负离子的离子液体中,开发了一个亚铜盐催化的Z-型溴代烯烃与硫族元素的交叉偶联反应,为立体选择性的制备Z-型烯基硫醚或烯基硒醚类化合物提供了一个新的方法;在此反应体系中,离子液体不仅起到了反应溶剂的作用,而且还起到了金属催化剂的配体和中和反应副产物的碱的作用。

Was applied to the AD reaction of eight olefins in PEG/NMO system according to the protocol of ligand 8. The yields and ees of the diols were 70~90% and 77~96%(except for trans-5-decene and ally naphthyl ether) respectively.

在与8相同的催化反应条件下,手性配体9催化八种烯烃的AD反应得到的化学产率和ee值分别为70~90%和77-96%(反式-5-癸烯和萘基烯丙基醚除外)。

In addition, the invention further relates to a catalyzer combination used for polymerizing a conjugated dialkene monomer and the anions of an optional mono-vinyl aromatic hydrocarbon into a polydiene polymer having high and medium vinyl content. The catalyzer combination comprises an organolithium compound used as an anionic polymerization initiator, at least an alkali metal alkoxide compound expressed by the formula as a structure regulator.

此外,本发明还涉及一种用于将共轭二烯烃单体和任选的单乙烯基芳烃阴离子聚合成具有中高乙烯基含量的聚二烯聚合物的催化剂组合物,其包含作为阴离子聚合引发剂的有机锂化合物,和作为结构调节剂的至少一种式所示的碱金属醇盐化合物。

The result of potassium malonyloxyborohydride as a new hydroboration reagent reacts with terminal alkenes and alkynes is described.

介绍新的硼氢化试剂丙二酰氧基硼氢化钾与链端烯炔烃的作用,烯烃的硼氢化物在PTC条件下,插入∶CCl2 ,可得饱和羧酸;炔烃则难以与之硼氢化。

This novel reagent was treated with LDA to produce polystyrene-supported a-seleno carbanions, which reacted with alkyl halides and epoxides, followed by stereospecific selenoxide syn-elimination to give olefins and allylic alcohols respectively.

它与LDA反应形成α—硒基稳定的碳负离子,再与卤代烃或环氧化合物发生α—烷基化反应,烷基化后的树脂可以在30%的双氧水中进行氧化-消除,以良好产率和较高纯度合成了取代烯烃或烯丙基醇。

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推荐网络例句

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称;三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起,称之为挽歌体诗人或者史诗诗人,他们被称为诗人,似乎只是因为遵守格律写作,而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。

This is not paper type of business,it's people business,with such huge money involved.

这不是纸上谈兵式的交易,这是人与人的业务,而且涉及金额巨大。