Polymer-Supported Chiral Dirhodium(II) Complex: Highly Durable and Recyclable Catalyst for Asymmetric Intramolecular C-H Insertion Reactions
Polymer-Supported Chiral Dirhodium(II) Complex: Highly Durable and Recyclable Catalyst for Asymmetric Intramolecular C-H Insertion Reactions
复制标题
聚合物支持的手性二铑(II)络合物：用于不对称分子内C-H插入反应的高度耐用且可回收的催化剂
DOI：
10.1002/anie.201003730
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
S.
中科院分区：
文献类型：
--
作者：
Takeda;K.; Oohara;T.; Anada;M.; Nambu;H.; Hashimoto;S.
手性二铑（II）配合物是重氮羰基化合物的各种不对称卡宾转化的高效催化剂，包括环丙烷化、C2 H4插入和重排或通过叶立德生成的环加成。[1]尽管已经报道了许多系统提供大于90%ee的对映选择性，但是手性二铑（II）络合物的高成本[2，3]和催化剂回收和再循环的困难是其在药物生产中应用的主要限制因素。非均相催化剂的潜在益处包括促进催化剂与产物的分离和简化催化剂再循环。在过去的几十年中，大量的注意力已经被用于开发用于多相化均相手性催化剂的方法。[4]然而，由几个独立的手性配体组成的聚合物负载催化剂的报道有限。[4，5]将手性二铑（II）络合物接枝到载体上的一个重大挑战是保持母体均相催化剂周围的手性环境。[6，7]在此背景下，Doyle等人报道了手性二铑（II）甲酰胺化物如[Rh 2（5S-MEPY）4]（1;图1），可以在NovaSyn Tentagel羟基树脂和梅里菲尔德树脂上通过与吡咯烷酮配体之一的酯键实现;这种固定化导致有效的和可重复使用的环丙烷化催化剂，其产率和选择性与均相催化剂相当。[8]Davies等人开发了一种用于固定手性四脯氨酸二铑（II）催化剂如[Rh 2（S-DOSP）4]（2）的新方法，通过使用高度交联的大分子-
Chiral dirhodium (II) complexes are highly effective catalysts for a diverse array of asymmetric carbene transformations of diazocarbonyl compounds, including cyclopropanation, CÀH insertion, and rearrangement or cycloaddition via ylide generation.[1] Although a number of systems have been reported to provide enantioselectivities greater than 90% ee, the high cost of chiral dirhodium (II) complexes [2, 3] and the difficulty in catalyst recovery and recycling are major limiting factors for their application in pharmaceutical production.The potential benefits of heterogeneous catalysts include facilitation of catalyst separation from products and simplification of catalyst recycling. During the past few decades, a great deal of attention has been paid to developing methods for heterogenizing homogeneous chiral catalysts.[4] However, there have been limited reports on polymer-supported catalysts composed of several independent chiral ligands.[4, 5] A significant challenge in grafting chiral dirhodium (II) complexes to supports is maintaining the chiral environment around the parent homogeneous catalysts.[6, 7] In this context, Doyle et al. reported that immobilization of chiral dirhodium (II) carboxamidates such as [Rh2 (5S-MEPY) 4](1; Figure 1), could be achieved on NovaSyn Tentagel hydroxy resin and Merrifield resin through an ester linkage to one of the pyrrolidinone ligands; this immobilization led to effective and reusable cyclopropanation catalysts with yields and selectivities comparable to those of the homogeneous catalysts.[8] Davies et al. developed a novel approach for the immobilization of chiral dirhodium (II) tetraprolinate catalysts such as [Rh2 (S-DOSP) 4](2), by using a highly cross-linked macro-