Iridium-catalyzed highly selective reactions

铱催化的高选择性反应

基本信息

批准号：
18550098
负责人：
TAKEUCHI Ryo
金额：
$ 2.64万
依托单位：
Aoyama Gakuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18550098/
关键词：
iridium allylic alkylation asymmetric synthesis phosphoramidite cyclotrimerization regioselectivity

项目摘要

We have studied the following reactions.(1) Asymmetric allylic alkylation is one of the most powerful tools for constructing a new chiral center via a carbon-carbon bond-forming reaction from an achiral substrate. A challenging topic in this area is the regio- and enantioselective allylic alkylation of nonsymmetrical substrates. Chiral phosphoramidite ligands have become important in transition metal-asymmetric synthesis. Helmchen first used binaphthol-based phosphoramidites for iridium-catalyzed enantioselective allylic alkylation. We designed a novel phosphoramidite P(OR)_2(amide)ligand. The planarity of the amide group strongly contributes to a more rigid chiral space. Furthermore, such a phosphoramidite ligand is expected to act as a chiral bidentate ligand through coordination of the carbonyl oxygen and phosphorous atom to the central metal. The efficiency of the ligand was examined by the reaction of cinhamyl acetate with diethyl sodiomalonate in the presence of 2 mol% of [Ir(cod)Cl]_2 and 4 mol% of ligand. The best result was obtained with a ligand bearing an oxazolidinone moiety. The alkylated product was obtained in 94% yield with 93% ee without LiCl.(2) Polysubstituted benzenes are a common structural component of naturally occurring biologically active molecules. The regioselective cyclotrimerization of two or three different monoynes is a new and efficient route to polysubstituted benzenes. However, it can be difficult to control the regioselectivity. Methyl propiolate reacted with 2 molecules of 1-alkyne to give 3, 5-disubstituted benzoate in high yield in the presence of a catalytic amount of [Ir(cod)Cl]_2 and FDPPE. The reaction of ethynyl p-tolyl sulfone with various 1-alkynes gave the corresponding products in high yields

我们已经研究了以下反应。（1）不对称的烯丙基烷基化是通过Achiral底物通过碳碳键形成反应来构建新手性中心的最强大工具之一。该领域的一个具有挑战性的话题是非对称底物的区域和对映选择性烯丙基烷基化。手性磷氧化岩配体在过渡金属合成中变得重要。 Helmchen首先使用基于双硫醇的磷光属地进行了虹膜催化的对映选择性烯丙基烷基化。我们设计了一种新型的磷酸磷酸岩P（OR）_2（酰胺）配体。酰胺组的平面性强烈促进了更僵化的手性空间。此外，这种磷光岩配体有望通过将羰基氧和磷原子配位与中央金属的磷酸原子配位起到手性生物性配体。在存在[IR（COD）CL] _2和4 mol％的配体的2 mol％的情况下，通过乙酸乙酸酯与二乙基二氧化二甲酸二乙基的反应来检查配体的效率。最好的结果是用带有恶唑烷酮部分的配体获得的。在没有LICL的93％EE的情况下以94％的产量获得了烷基化产物。（2）多卵巢生成的苯苯甲苯是天然存在的生物活性分子的常见结构成分。两个或三个不同的单体的区域选择性环三聚体是通往多卵巢苯苯的新途径。但是，可能很难控制区域选择性。甲基丙酸甲酯与2个分子的1-烷基反应，在存在催化量的[ir（cod）Cl] _2和fdppe的情况下，产生了3个，5个取代的苯甲酸酯。乙基尼尔p-甲基磺基与各种1-Alkynes的反应给出了相应的产物高产量