Development of Selective Oxidation of Alkenes by Heterometallic Catalysts and Its Synthetic Application

在合成化学领域中，当然需要开发在区域和立体选择性方面高度受控的有效催化反应。借助于金属络合物催化剂提供了解决该问题的途径。从这一观点出发，我们的目标是通过使用异金属催化剂来发展烯烃的立体选择性和区域选择性氧化。本研究取得的主要结果如下：1.我们已经开发了钯（II）催化的不对称缩醛化的甲基丙烯酸衍生物轴承光学活性2-恶唑烷酮，从其中光学活性3-羟基-2-甲基丙醛是在高对映体过量。该反应可大规模进行，所得醛可作为合成1 β-甲基碳青霉烯衍生物氮杂环丁酮衍生物的有用结构单元.在PdCl_2、CuCl和六甲基磷酰三胺组成的异金属催化剂存在下，N-烯丙基酰胺和内酰胺与分子氧反应，区域选择性地生成相应的醛。另一方面，当水存在于反应体系中时，它产生相应的甲基酮。迄今为止，在这种类型的氧化中，区域选择性的这种完全逆转还没有先例。

Development of effective, catalytic reactions which are highly controlled in terms of regio-and stereoselectivity is certainly required in the field of synthetic chemistry. Access to this problem is provided by the aid of metal complex catalysts. From such a view point, we have aimed to develop stereo-and regioselective oxidations of alkenes by using heterometallic catalysts. The major results obtained in this study are as follows.1. We have developed palladium(II)-catalyzed asymmetric acetalization of methacrylic derivatives bearing optically active 2-oxazolidinones, from which optically active 3-hydroxy-2-methylpropanal is obtainable in high enantiomer excess. The reaction can be performed in large scale, and the aldehyde obtained was found to serve as a useful building block for the synthesis of an azetizinone derivative of 1beta-methylcarbapenem precursor.2. Treatment of N-allylamides and lactams with molecular oxygen in the presence of a heterometalic catalyst consisting of PdCl_2, CuCl, and hexamethylphosphoric triamide was found to produce the corresponding aldehydes regioselectively. On the other hand, when water is present in the reaction system, it gives the corresponding methyl ketones. There is so far no precedent for such a complete reversal of the regioselectivity in this type of oxidations.