Molecular Mechanisms of Regio-and Stereoselections in the Reactions of Charcogen Coumpounds

随着化学家的兴趣扩展到原子序数较高的元素的化学，出现了许多主要为第一排元素发展的价概念无法解释的情况。在这项研究中，我们对现有的反应性理论进行了深入的重新研究，并提出了一种新的反应性的理论处理方法。我们已经为每个积极参与与试剂形成新键的反应物分子定义了反应轨道，这些分子位于反应位置周围。通过这种方法，我们能够估计反应中心的局部给电子和接受电子的势，从而使比较不同分子的反应性成为可能。为了证明这一理论的适用性，以及更清楚地区分碳原化合物和周围有其他元素的化合物，我们将这一理论应用于碳pi共轭物种中的替代效应，其中…丰富。有更多的实验数据可用。实验结果表明，与现有理论相比，我们的新理论能更好地解释实验观测结果。我们还将该理论应用于烯丙基化合物的反应，取得了成功的结果。为了揭示硒化合物不对称重排反应的分子机理和控制反应路径的因素，我们进行了从头算分子轨道计算。还对甲基锂与含二茂铁基的恶唑类化合物的反应进行了计算，阐明了锂优先加成氮中心的原因。在实验方面，我们首次合成了具有光学活性的[R，S；R，S]-和[S，R；S，R]-双[2-[1-(二甲氨基)乙基]二茂铁基]二硒化合物，并证明了不对称的亚硒消除和不对称的[2，3]Sigma重排反应是非常有效的。为了研究过渡金属配合物的不对称催化反应，我们合成了多种含二茂铁基的碳原化合物。研究表明，含手性配体的Rh(I)络合物用于酮的硅氢化反应，高产率地得到了手性醇。较少

As the interests of chemists expands to chemistry of the elements with higher atomic numbers, there appear many cases which cannot be interpreted by the valence concept that has been developed mainly for the first row elements. In this research, we have thoroughly reinvestigated the presenting reactivity theories and proposed a novel theoretical treatment of reactivity. We have defined the reactive orbital for each reactant molecule that participates actively in the formation of new bonds with a reagent, being localized around the reaction sites. In this way, we are able to estimate the local electron-donating and accepting potentials of the reaction sites, making it feasible to compare the reactivity of different molecules. With a view to proving the applicability of this theory and to making clearer the difference between charcogen componds and compounds with other elements around, we have applied the theory to the subsituent effects in the carbon pi conjugated species in which ample … More experimental data are available. It has been demonstrated that our new theory interprets the experimental observations much more satisfactorily compared with the existing theories. We have also applied the theory to the reaction of allylic compounds, obtaining successful results. To disclose the molecular mechanism and the factors controlling the reaction path for an asymmetric induction in sigmatropic rearrangements of selenium compounds, we have carried out ab initio MO calculations. Calculation have also been carried out on the reaction between methkyllithium and oxazolines having a ferrocenyl group, elucidating the reason why lithium adds preferentially to the nitrogen center. The results of these works are being prepared for publishing.On the experimental side, we have synthesized for the first time optically active [R,S ; R,S] - and [S,R ; S,R]-Bis [2- [1- (dimethyamino) ethyl] ferrocenyl] Diselenides and have demonstrated asymmetric selenoxide elimination and asymmetric [2,3] sigmatropic rearrangement take place very efficiently.To study asymmetric catalytic reacttions by the use of transition metal complexes, we have synthesized a variety of charcogen compounds having ferrocenyl groups. It was been shown hydrosilylation of ketones by using Rh (I) complexes having chiral ligands gives chiral alcohols at high yields. Less