取代物

The results show thatthe substitutions containing sulfur atom in the pyrazole ring remarkably affectthe steric and electronic properties of the pyrazole ligands.

因此，我们研究了吡唑环上带上S原子取代基对形成双吡唑烷配体及其与VIB金属羰基配合物的光化学反应的影响。

A few of aryl pyridylalkyl ethers were synthesized by Mitsunobu reaction from substituted phenols 1a-b and pyridyl alcohols 2a-e at room temperature in 45%~70% yields.

在室温下，以取代苯酚1a-b和吡啶烷基醇2a-d为原料通过Mitsunobu反应合成了相应的芳基吡啶烷基醚，反应收率为45%￣70%，反应物2和1之比为1.11∶。

"What we're hoping to have happen is to catch early and remineralize them," said Sally Marshall, a professor at the University of California at San Francisco.

牙釉质和牙本质构成牙体最坚固的部分，它们将取代金或陶器填充物用于恢复牙齿的正常功能。

Our main research work has been focused on the synthesis, characterization of substituted salicylaldehyde Schiff bases and their complexes, which are not reported in articles now. There are twenty-one new compounds in total.

本论文研究了目前未见国内外文献报道的、水杨醛中苯环上含有取代基的水杨醛缩脱氢枞胺Schiff碱及其金属配合物的合成与表征，共计获得了21个新的化合物，从而为后期生物活性的测定及不对称催化提供研究基础和实验样品。

In addition, the second rare earth, such as Tb〓、La〓、Gd〓 and Y〓, was separatively doped in the europium carboxylic complex and replaced some europium ions. The luminescence properties were discussed to research the effect of the second ions to europium ions.

本文将第二种稀土离子Tb〓、La〓、Gd〓和Y〓分别掺入到铕的羧酸配合物中，让第二种稀土离子部分取代铕离子，并详细地研究了不同含量的第二种稀土离子对中心发光离子铕荧光性质的影响。

The present invention concerns the compounds having the formula N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs, esters and metabolites thereof, wherein R1 and R8 each are H, optionally substituted C1-6alkyl, C2-6alkenyl, C3-7cycloalkyl, aryl, Het1, Het2; R1 may also be a radical of formula (R11aR11b)NC(R10aR10b)CR9-; t is 0, 1 or 2; R2 is H or C1-6alkyl; L is -C-,-O-C-,-NR8-C-,-O-C1-6alkanediyl-C-,-NR8-C1-6alkanediyl-C-,-S2-,-O-S2-,-NR8-S2 ; R3 is C1-6alkyl, aryl, C3-7cycloalkyl, C3-7cycloalkylC1-4alkyl, or arylC1-4alkyl; R4 is H, C1-4alkylOC, carboxyl, aminoC, mono- or di(C1-4alkyl)aminoC, C3-7cycloalkyl, C2-6alkenyl, C2-6alkynyl or optionally substituted C1-6alkyl; R5 and R6 are H or C1-6alkyl.

本发明涉及右式化合物其N-氧化物、盐、立体异构形式、外消旋混合物、前药、酯及代谢物，其中R 1 及R 8 各是氢、C 1-6 烷基、C 2-6 烯基、C 3-7 环烷基、芳基、Het 1 、Het 2 ；R 1 也可以是式(R 11a R 11b )NC(R 10A R 10b )CR 9 -之基；t是0、1或2；R 2 是氢或C 1-6 烷基；L是-C-、-O-C-、-NR 8 -C-、-O-C 1-6 烷二基-C-、-NR 8 -C 1-6 烷二基-C-、-S 2 -，-O-S 2 -、-NR 8 -S 2 -；R 3 是C 1-6 烷基、芳基、C 3-7 环烷基、C 3-7 环烷基C 1-4 烷基或芳基C 1-4 烷基；R 4 是氢、C 1-4 烷基OC、羧基、氨基C、一-或二(C 1-4 烷基)氨基C、C 3-7 环烷基、C 2-6 烯基、C 2-6 炔基或任选被取代的C 1-6 烷基；R 5 及R 6 是氢或C 1-6 烷基。

Influence of steric effect on asymmetric transformation is more prominent.

底物中取代基的空间效应和电子效应也影响不对称转化的结果，但空间效应的影响更加显著。

In the presence of DMSO as co-solvent and under vigorous agitation, baker\'s yeast in water was found to reduce substituted fluorenones to the corresponding fluorenols in good to excellent enantioselectivies (52%~ 100% ee). The experimental results clearly revealed that when mass transfer limitations are overcome, baker\'s yeast is able to reduce even highly sterically hindered ketones, such as substituted fluorenones.

在强烈的搅拌、并使用DMSO作为底物助溶剂的反应条件下，面包酵母对取代芴酮显示出较高得还原活性，得到立体选择性很高的相应的芴醇(52%～100%ee)。

The results are following:(1)We investigated the influence of the positional isomeric effect on structures.Due to the less space-crowding,it is easier for 3-pytpy to behave as bridging ligand than 2-pytpy under the same reaction conditions,while,it is easier for 2-pytpy to function as tridentate chelating ligand to construct supramolecular structures.

研究结果如下：(1)研究了两个吡啶取代三联吡啶配体的位置异构效应对配合物结构的影响。3-pytpy配体比2-pytpy具有更小的空间位阻，在相同的合成条件下容易以单-三齿桥联方式配位；而2-pytpy更易以三齿螯合形式配位，通过π…π堆积作用形成超分子结构。

The combinative effect of the fluorine substitute and the bridging unit can make complex 2 as a highly active and selective catalyst for ethylene trimerization.

氟原子效应和桥碳原子上大取代基效应两者结合在一起，可以使络合物2成为一种高活性和高选择性的乙烯三聚催化剂。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。