Nickel catalysis hydrocyanation

The hydrocyanation of vinylarenes ° has been studied by a DuPont team using nickel catalysis. The hydrocyanation of 6-methoxy-2-vinylnaphthalene (2.219) affords the product (2.220), where the enantiomeric excess is strongly dependent upon the electronic nature of the bisphosphinite ligand (2.12). Hydrolysis of the nitrile (2.220) affords the nonsteroidal anti-inflammatory drug Naproxen. This nickel-catalysed procedure has also been applied with some success to the regiose-lective, asymmetric hydrocyanation of 1,3-dienes such as 1-phenyl-1,3-butadiene (2.221) to give the 1,2-adduct (2.222) with ees between 50 and 83%. ... 

The addition of HCN to olefins catalyzed by complexes of transition metals has been studied since about 1950. The first hydrocyanation by a homogeneous catalyst was reported by Arthur with cobalt carbonyl as catalyst. These reactions gave the branched nitrile as the predominant product. Nickel complexes of phosphites are more active catalysts for hydrocyanation, and these catalysts give the anti-Markovnikov product with terminal alkenes. The first nickel-catalyzed hydrocyanations were disclosed by Drinkard and by Brown and Rick. The development of this nickel-catalyzed chemistry into the commercially important addition to butadiene (Equation 16.3) was conducted at DuPont. Taylor and Swift referred to hydrocyanation of butadiene, and Drinkard exploited this chemistry for the synthesis of adiponitrile. The mechanism of ftiis process was pursued in depth by Tolman. As a result of this work, butadiene hydrocyanation was commercialized in 1971. The development of hydrocyanation is one of tfie early success stories in homogeneous catalysis. Significant improvements in catalysts have been made since that time, and many reviews have now been written on this subject. ... 

Nickel is frequently used in industrial homogeneous catalysis. Many carbon-carbon bond-formation reactions can be carried out with high selectivity when catalyzed by organonickel complexes. Such reactions include linear and cyclic oligomerization and polymerization reactions of monoenes and dienes, and hydrocyanation reactions [1], Many of the complexes that are active catalysts for oligomerization and isomerization reactions are supposed also to be active as hydrogenation catalysts. 

In an extension of an early work on the nickel-catalyzed addition of hydrogen cyanide to unsaturated compounds, a basic reaction in various large-scale processes in the polymer industry, the hydrocyanation of butadiene (equation 15) and the efficiency of catalysis of this reaction by low-cost copper salts has been studied extensively by Belgium researchers47,48. 

Cobalt B12 Enzymes Coenzymes Copper Hemocyanin/Tyrosinase Models Heterogeneous Catalysis by Metals Hydride Complexes of the Transition Metals Hydrocyanation by Homogeneous Catalysis Hydrogen Inorganic Chemistry Mechanisms of Reaction of Organometalhc Complexes Nickel OrganometaUic Chemistry Ohgomerization Polymerization by... 

The stereoselectivity of the reaction was the target of several investigations. The results clearly establish that the addition of hydrogen cyanide to olefins is stereospecifically syn [33, 46 9]. Thus, reaction of terminal, deuterium-substituted olefins yields the corresponding syn addition products. Hydrocyanation of 4-t-butyl cyclohex-1-ene with deuterium cyanide confirmed these results. It is found that the stereospecifity is independent of the catalyst metal employed, since both nickel° and palladium catalysis give the syn addition products [50]. 

Nonactivated olefins fail to react even under strenuous conditions with cyanide anion catalysis. Due to this lack of reactivity coupled with the inherent desirability of the products, much research has focused on developing catalysts for the hydrocyanation of these nonactivated olefins. This has led to nickel, palladium, copper, and cobalt-based catalysts effective at 25-125°C with or without a solvent. Most were developed for the hydrocyanation of unactivated olefins, but many are equally applicable for oAer olefins. For example, much work has been reported on butadiene hydrocyanation employing all of the catalysts mentioned above except palladium. 

Profenes or aryl-2-propionic acids are a family of antiinflammatory agents representing an enormous market in pharmacy. Several approaches of syntheses of these compounds using asymmetric catalysis have been used with success. For example, asymmetric hydrocyanation (see Chap. 14) of an olefin by nickel(O) to which a phosphinite ligand derived from glucose is coordinated leads to a nitrile precursor of naproxene with a 96% yield and 85% e.e. ... 

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