丙二烯

The preparation of potassium malonyloxyborohydride in situ and its seletive hydroborating alkene are described.

介绍了丙二酰氧基硼氢化钾的制备及其原位与烯烃的选择性硼氢化。

Products has led caprate cobalt, cobalt naphthenate, TY series of high-performance polyimide resin, FLQ type latent epoxy curing promoting agent, diallyl bisphenol A Product dozens of top-five.

主导产品有癸酸钴、环烷酸钴、TY系列高性能聚酰亚胺树脂、FLQ型潜伏性环氧固化促进剂、二烯丙基双酚A五大类数十种产品。

While the basicity of the N-atom is stronger, more active second generation catalyst is indispensable and the temperature needs to be reached 150℃, and mixture of pyrrolidine and pyrrole was gained.

研究结果表明微波辐射条件下氮原子的碱性强弱对于二烯丙基胺发生关环复分解反应具有很大的影响：当底物的碱性比较强时，必须使用活性更高的第二代Grubbs催化剂，且温度需升至150℃反应才能顺利发生，得到光学纯吡咯啉和吡咯的混合物。

Via comprehensive computations, the possibilities of vinylidene and allene intermediates were excluded, and the reaction mechanism was found to contain the following three steps:(1) gold-catalyzed cyclization to give the cyclic intermediate,(2) the cyclic intermediate undergoing a 1,3-H migration to give a more stable intermediate, with the assistance of water-cluster,(3) finially, the 1,2-H or 1,2-silyl migration occuring for generation of the observed product.

通过对各种可能的反应路径的进行计算和比较，排除了亚甲基卡宾和连二烯中间体的可能性，并确定该异构化反应机理包含以下三个步骤：（1）炔丙基吡啶反应在金催化条件下发生分子内的成环得到环状中间体；（2）环状中间体在水分子簇的协助下优先发生1，3-氢迁移反应，异构化得到更为稳定的中间体；（3）最后再进行1，2-氢迁移或是1，2-硅烷基团迁移即得到实验中所观察到的环异构化产物。

4R,5S,6R-5,6-Bis-allyl-6-aldehyde-γ-hexanelactone I-145 was prepared from D-arabinose by six steps. Compound I-145 underwent Mukaiyama-type intramolecular aldolization to produce bicyclooctane I-147 stereospecifically.

我们以D-阿拉伯糖为起始原料，经六步反应，得到(4R，5S，6R)-5， 6-二烯丙氧基-6-醛基-γ-己酸内酯I-145，然后I-145发生分子内的Mukaiyama式aldol缩合反应，完全立体专一性地得到环化中间体I-147。

In this catalyst system, the Knoevenagel condensations of a series of aromatic aldehydes with malononitrile or ethyl cyanoacetate were programmed and a mechanism was postulated as well. When aromatic aldehydes reacted with ethyl cyanoacetate, the corresponding alkenes proved to be E-isomers by 1H NMR.

在该反应体系中考察了一系列芳香醛和丙二氰、氰基乙酸乙酯的缩合反应，并推测了Knoevenagel缩合反应的机理，芳香醛与氰基乙酸乙酯缩合产物经1H NMR检测为E式烯烃。

Objective To study the effects of diallyl trisulfide on apoptosis of human leukemia cells HL-60 and the probable mechanism involved.

目的 研究二烯丙基三硫对HL-60细胞凋亡的影响及其作用机制。

METHODS: diallyl trisulfide coated stent and the control stent were implanted into distal and proximal left circumflex coronary arteries of 20 dogs, respectively.

进行冠状动脉左回旋支支架置入术的犬，将二烯丙基三硫化物涂层支架和对照支架分别置入左回旋支的远端和近端。

The effect of controlling microstickies in recycled newspaper pulp and the effect on the resultant paper property of some fixatives,including inorganic polyaluminum chloride,organic polyamine,polydiallydimethyl ammonium chloride,and high cationic starch,were investigated in this paper.

分别以聚合氯化铝、聚胺、聚二甲基二烯丙基氯化铵和高取代度阳离子淀粉作为固定剂，研究了它们对废纸浆中微胶黏物的控制效果及对纸页性能的影响。

The ultrathin multilayer film of poly (diallyldimethylammonium chloride) and polyvinylidene fluoride has been prepared by the layer-by-layer static self-assembly method. The PVDF/PDDA multilayer film with the thickness ranging from about 30nm to 150 nm the thickness of each layer is about 9nm.

聚二烯丙基二甲基氯化铵和极化处理后的聚偏氟乙烯复合超薄膜是通过层与层的静电自组装方法制备的，厚度约30～150 nm，每层膜厚度约为9 nm。

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。