Catalytic asymmetric allylic alkylation in water with a recyclable amphiphilic resin-supported P,N-chelating palladium complex
Catalytic asymmetric allylic alkylation in water with a recyclable amphiphilic resin-supported P,N-chelating palladium complex
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DOI：
10.1021/ja005866j
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发表时间：
2001-03-28
影响因子：
15
通讯作者：
Shibatomi, K
中科院分区：
文献类型：
--
作者：
Uozumi, Y;Shibatomi, K
在水中用可回收的固定化手性催化剂进行高对映选择性反应是合成有机化学的一个重要目标。1，2我们最近报道了几个钯催化的反应，包括π-烯丙基取代，3a，d羰基化，3c的Heck反应，3c和Suzuki-Miyaura的交叉偶联，3b通过钯-膦配合物与两亲性聚苯乙烯-聚乙二醇接枝共聚物在水中发生。5这些令人鼓舞的结果促使我们设计了新型的负载在两亲性PS-PEG树脂上的手性配合物，在几种类型的过渡金属催化的不对称有机转化中表现出催化活性和对映体选择性。6我们设计并合成了一种新型的P，N-螯合型PS-PEG树脂手性配体，用于钯催化的水中不对称烯丙基取代反应，对映体选择性高达99/1。在对新型手性试剂设计的研究中，7个具有吡咯-[1，2-c]咪唑酮骨架的高官能化光学活性双环胺通过多样性的方法被确定为有效的手性试剂。结果表明，一种以吡咯并[1，2-c]咪唑酮骨架为基本手性单元的新型P，N-螯合型手性配体可以很容易地固定在PS-PEG树脂上以实现高对映选择性多相催化(方案1)。(3R，9As)-(2-芳基-3-(2-二苯基膦)苯基)-四氢-1H-咪唑并[1，5-a]吲哚-1-酮(1)是由(S)-吲哚-2-羧酸、4-{3-甲氧基丙基}苯胺和2-(二苯基)苯甲醛容易合成的。
Highly enantioselective reactions in water with recyclable immobilized chiral catalysts are an important goal in synthetic organic chemistry. 1, 2 We recently reported that several palladiumcatalyzed reactions, 3 including π-allylic substitution, 3a, d carbonylation, 3c the Heck reaction, 3c and Suzuki-Miyaura cross-coupling, 3b took place in water4 by use of palladium-phosphine complexes bound to an amphiphilic polystyrene-poly (ethylene glycol) graft copolymer (PS-PEG) resin. 5 These encouraging results prompted us to design new chiral complexes supported on the amphiphilic PS-PEG resin, which would exhibit catalytic activity as well as enantioselectivity in water in several types of transition metalcatalyzed asymmetric organic transformations. 6 We describe herein the design and preparation of a new P, N-chelate chiral ligand bound to PS-PEG resin and its use for palladium-catalyzed asymmetric allylic substitution in water, in which enantioselectivity up to 99/1 was achieved.During our studies on the design of new chiral reagents, 7 highly functionalized optically active bicyclic amines having a pyrrolo-[1, 2-c] imidazolone framework were identified as effective chiral agents through a diversity-based approach to new chiral amine catalysts. 8 The results indicated that a novel P, N-chelate chiral ligand having the pyrrolo [1, 2-c] imidazolone skeleton as a basic chiral unit would be readily immobilized on the PS-PEG resin to achieve highly enantioselective heterogeneous catalysis in water (Scheme 1).(3R, 9aS)-(2-Aryl-3-(2-diphenylphosphino) phenyl)-tetrahydro-1H-imidazo [1, 5-a] indole-1-one (1), which was readily prepared from (S)-indoline-2-carboxylic acid, 4-{3-(methoxycarbonyl) propyl} aniline, and 2-(diphenylphosphino) benzaldehyde