氧化合物

In summary, 4, 6-dimethoxy-2-substituted pyrimidine benzylamine is chosen as a lead compound based on the possibility of synthesis, optimization, and the herbicidal activity.

考虑到合成的可行性、分子结构的可修饰性和除草活性的大小，确定4，6-二甲氧基-2-取代嘧啶苄胺类化合物为除草剂的先导结构。

The high post-emergent and pre-emergent herbicidal activity at low dosage of 75 g ai/hm~2 can be found for some N-(mono-substituted phenyl)-2-(4, 6-dimethoxypyrimidin-2-yloxy)benzylamine derivatives.

2氧桥单取代羧酸酯嘧啶苄胺类化合物在75 g ai／hm~2低剂量下，芽后和芽前除草活性不高。

Therelative rates of the Rh-mediated carbenoid insertion into the benzylic C - H bonds of aseries of para-substituted phenyl substrates: methyl 2-diazo-3-oxo-6-(4-substituted phenyl)-4-propylhexanoate 47a - g, have been measured by an indirect intramolecular competitionmethod under the condition in which the possible steric and conformational effects have beenminimized.

为了将立体因素和构象因素最大程度减小，以便较为准确地评价电子效应对该反应的影响，设计并合成了不同对位取代基的化合物4-丙基-6-(4-取代苯基)-2-重氮基-3-氧代己酸甲酯47a-g，并研究了它们在不同Rh催化剂作用下的分子内C-H插入反应。

Bulky and electron-rich MOP-type phosphine ligand 2-ditertbutylphosphino-2'-isopropyloxy- 1,1'-binaphthyl (L1) shows good catalytic activity in palladium-catalyzed α-arylation of 1,3-dicarbonyl compounds.

富电子、大位阻MOP型烷基膦配体2-二叔丁基膦-2'-异丙氧基-1，1'-联萘(L1)在钯催化的1，3-二羰基化合物的α-芳基化反应中显示了较好的催化活性。

Bulky and electron-rich MOP-type phosphine ligand 2-ditertbutylphosphino-2 -isopropyloxy 1,1 -binaphthyl (L1) shows good catalytic activity in palladium-catalyzed α-arylation of 1,3-dicarbony compounds.

富电子、大位阻MOP型烷基膦配体2-二叔丁基膦－2'-异丙氧基－1，1'-联萘(L1)在钯催化的1，3-二羰基化合物的α-芳基化反应中显示了较好的催化活性。

The tryptophan residues play important roles in DNA photoreactivation catalyzed by CPD photolyases. We have investigated the action mechanism concerning Trp in DNA photoreactivation, and obtained the results as follows: 1 We proposed a mechanism of photosensitized splitting of CPDs by Trp and Trp-containing peptides. 2 Quantum yields of splitting of the model compounds that a Trp linked covalently a CPD were obtained under 290 nm light in various solvents, these values changing with solvent, range from 0.01 to 0.5. 3 Utilizing pulse radiolysis technique, splitting processes were observed in aqueous solution of the CPDs with hydrated electron and some oxidative species (such as hydroxyl radical, bromic radical and azide radical), and obtained their rate constants. In the case of interaction between CPD and hydrated electron, splitting of the CPD anion, and pyrimidine anion transfer an electron to FAD or Rf, were observed. The process rate was slower one order more than that in photolyase. Minor, but highly mutagenic UV-light-induced lesions are (6-4) photoproducts, which are repaired by (6-4) photolyases. These enzymes, discovered in 1993, are not well characterized and their mechanism is still under investigation.

我们研究它的作用机理，获得以下结果：1）建立了色氨酸及其肽对嘧啶二聚体光敏化裂解的直接修复作用机理模型；2）获得了色氨酸共价键连接于嘧啶二聚体的化合物在多种溶剂中290nm光辐照裂解的量子效率，其值随溶剂而变化，范围在0.01-0.5；3）运用脉冲辐解观察到嘧啶二聚体与水合电子和一些氧化性的自由基作用裂解过程，得到相应速率常数；对二聚体与水合电子作用发生裂解以及向FAD返还电子的过程进行了体外模拟；4）（6-4）光解酶的作用机理中一个关键假定是氧杂环丁烷中间体在接受电子后能自发裂解，恢复二嘧啶的结构。

A process for the carbonylation of allylic butenyl ether (for example, methyl crotyl ether, 3-methoxybutene-1 and mixtures thereof) or mixture of butadiene and alcohol and production of beta-gamma unsaturated carboxylic acid esters (for example, methyl-3-pentenoate) utilizing a rhodium-containing catalyst for example, dicarbonylacetylacetonate rhodium(I or the like promoted with an iodide-containing compound (for example, HI, AlI3, SnI4, TiI4, CrI3, and CoI2 or the like).

一种将烯丙型丁烯基醚(如甲基巴豆基醚、3－甲氧基丁烯－1及其混合物)或者丁二烯与醇的混合物羰基化的方法，以及由含碘化物化合物(如HI、AlI3、SnI4、TiI4、CrI3和CoI2或等效物)促进，用含铑催化剂如二羰基乙酰丙酮酸铑(I或其等效物制备β－γ不饱和羧酸酯(如甲基－3－戊烯酸酯)的方法。

F. which belongs to the Celastraceae Tripterygium plant, its extraction acetylacetic ester was used in clinic preparation, the primary component is epoxy terpenoid lactone.

为卫矛科雷公藤属植物，临床制剂使用的是雷公藤根的乙酸乙酯提取物，主要成分为环氧二萜内酯类化合物。

Stone is from rock, and rock is consist of the mineral, the mineral contain iron is the source of the iron in stone products , iron element spread widely in natural world, but most of them appear to be compound, iron element is belong to medium activity metal, under high temperature is easily to be strongly acted with oxygen, sulfur, chlorine, and easily dissolve in abio-weak acid solution and strong hydrochloric acid solution, at the same time, the strong alkali solution also corrade the iron.

石材是岩石经加工后所产生的制品，岩石是由矿物组成的，其中含铁矿物是石材中铁质的来源。铁元素在自然界中分布甚广，但大多以化合物的方式出现，由于铁元素属中等活泼性的金属，在高温下易和氧、硫、氯等元素发生强烈反应，并易溶于无机稀酸和浓盐酸的溶液中，同时浓碱溶液也易侵蚀铁。

Result: 5 compounds were identified as eriodictyol (1), 5, 7-dihydroxy-3′, 4′-dimethoxy flavanone (2), oleanolic (3), 5, 7-dihydroxychromone (4) and homeriodictyol (5) by spectral evidences, in which homeriodictyol (5) had acceleration differentiation to PC12 cell.

结果：获得了5个主要化学成分，即北美圣草素(1)， 5，7-二羟基-3′，4′-二甲氧基-二氢黄酮(2)，齐墩果酸(3)， 5，7-二羟基色原酮(4)，高北美圣草素(5)。经活性筛选试验发现，化合物高北美圣草素(5)具有促PC12细胞分化作用。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！