权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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

我们研究了以下反应。(1)不对称烯丙基烷基化反应是从非手性底物通过碳-碳键形成反应构建新手性中心的最有力的工具之一。在这一领域的一个具有挑战性的课题是区域和不对称底物的烯丙基烷基化。手性亚磷酰胺配体在过渡金属不对称合成中具有重要的应用。Helmchen首先使用基于联萘酚的亚磷酰胺用于铱催化的对映选择性烯丙基烷基化。我们设计了一个新的亚磷酰胺P（OR）_2（酰胺）配体。酰胺基团的平面性强烈地有助于更刚性的手性空间。此外，预期这种亚磷酰胺配体通过羰基氧和磷原子与中心金属的配位而充当手性双齿配体。在2mol%[Ir（cod）Cl]_2和4mol%配体存在下，乙酸肉桂酯与丙二酸二乙酯的反应考察了配体的作用效果。用带有恶唑烷酮部分的配体获得最佳结果。在没有LiCl的情况下，以94%产率和93%ee获得烷基化产物。(2)多取代苯是天然存在的生物活性分子的常见结构组分。两个或三个不同单炔的区域选择性环三聚反应是合成多取代苯的一条新的有效途径。然而，控制区域选择性可能很困难。丙炔酸甲酯在催化量的[Ir（cod）Cl]_2和FDPPE存在下与2分子1-炔反应，高产率地合成了3，5-二取代苯甲酸酯。乙炔基对甲苯基砜与各种1-炔反应，高产率地得到了相应的产物