Catalytic hydrocyanation of olefins by nickel(0) phosphite complexes - effects of Lewis acids
Catalytic hydrocyanation of olefins by nickel(0) phosphite complexes - effects of Lewis acids
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DOI：
10.1021/om00079a008
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发表时间：
1984
期刊：
影响因子：
2.8
通讯作者：
C. A. Tolman;W. Seidel;J. D. Druliner;P. Domaille
中科院分区：
文献类型：
--
作者：
C. A. Tolman;W. Seidel;J. D. Druliner;P. Domaille
使用Ni[P(0-邻甲苯基)3]3催化剂将HCN加成到烯烃上的机理研究表明，该反应在温和条件下通过单烯或二烯插入HNiL3CN的镍氢键形成的(V-有机)-或(?j3-有机)氰化镍中间体进行。在某些情况下，RNiLmCN 中间体可以通过 NMR 和 IR 进行光谱鉴定。在负电性很强的R基团（例如由HNiL3CN与C2F4或丙烯腈的反应形成）的情况下，不会发生还原消除，并且催化剂因烯烃氢氰化而中毒。通过添加路易斯酸 (A) 助催化剂可以提高速率、催化剂寿命和产物线性度。光谱研究表明路易斯酸可以与氰化氢中间体的氮孤电子对强烈配位，形成HNiL3CN-A配合物。提出了路易斯酸对氢氰化作用的解释，其中涉及增加催化环物质中镍的浓度[在P(0-对甲苯基) 3 体系中]，加快碳-碳偶联从烷基镍氰化物络合物形成烷腈的速率，以及相对于不太拥挤的直链中间体使相对庞大的支链烷基中间体不稳定。通过均相镍催化剂将HCN加成到烯烃是工业中重要的成功故事之一。均相催化的应用。尽管从丁二烯大规模生产己二腈已有 10 多年的历史，但有关反应机理、特别是路易斯酸助催化剂的有趣作用的科学文献 1 发表的文章却很少。我们已经描述了一些相关的化学，包括 NiL4 配合物解离为 NiL3，3 HCN 氧化加成到 NiL 配合物得到 HNiLmCN4（L= 磷配体，= 3 或 4，m= 2 或 3），以及烯烃和腈反应得到（烯烃）NiL25 和（RCN）NiL3 配合物的研究。 50, 6 关于烯烃的研究最近报道了均相镍催化剂的氢氰化反应
Mechanistic studies on the addition of HCN to olefins using Ni [P (0-o-tolyl) 3] 3 catalyst show that the reactions proceed under mild conditions via (V-organo)-or (? j3-organo) nickel cyanide intermediates formed by the insertion of monoenes or dienes into the nickel-hydrogen bond of HNiL3CN. The RNiLmCN intermediates can be identified spectroscopically by NMR and IR in some cases. In the case of very electronegative R groups (formed for example from reactions of HNiL3CNwith C2F4 or acrylonitrile), reductive elimination does not occur, and the catalyst is poisoned for olefin hydrocyanation. Improved rates, catalystlifetimes, and product linearity can be obtained by the addition of Lewis acid (A) cocatalysts. Spectroscopic studies show that Lewis acids can coordinate strongly to the nitrogen lone-electron pairof hydride cyanide intermediates to form HNiL3CN-A complexes. An explanation of the effects of Lewis acids on hydrocyanation is proposed, which involves increasing the concentration of nickel in catalytic loop species [in the P (0-p-tolyl) 3 system], accelerating the rate of carbon-carbon coupling to form alkanenitriles from alkylnickel cyanidecomplexes and destabilizingrelatively bulky branched alkyl intermediates relative to less crowded linear ones.The addition of HCN to olefins by homogeneous nickel catalysts is one of the important success stories in the industrial application of homogeneous catalysis. In spite of the fact that adiponitrile has been produced on a large scale from butadiene for more than 10 years, 1 very little has been published in the scientific literature2 concerning the mechanism of the reactions, particularly the intriguing roles of the Lewis acid cocatalysts. We have described some related chemistry, including the dissociation of NiL4 complexes to NiL3, 3 the oxidative addition of HCN to NiL „complexes to give HNiLmCN4 (L= a phosphorus ligand,= 3 or 4, m= 2 or 3), and studies of reactions of olefins and nitriles to give (olefin) NiL25 and (RCN) NiL3 com-plexes. 50, 6 Studies on olefin hydrocyanation by homoge-neous nickel catalysts have recently been reported from