Catalytic oxidative synthesis of nitriles directly from primary alcohols and ammonia.
Catalytic oxidative synthesis of nitriles directly from primary alcohols and ammonia.
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DOI：
10.1002/anie.200900418
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发表时间：
2009-08
影响因子：
--
通讯作者：
T. Oishi;K. Yamaguchi;N. Mizuno
中科院分区：
文献类型：
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作者：
T. Oishi;K. Yamaguchi;N. Mizuno
腈类化合物在化学和生物学中是一类非常重要的化合物，它们被广泛用于生产药物、农用化学品和精细化学品。[1]芳香腈的合成方法主要有桑德迈尔反应和气相氨氧化法。[1]用化学计量的有害无机氰化物对烷基卤化物进行亲核取代是合成烷基腈的一般方法，并且经常伴随着卤化氢的消除，特别是在大体积烷基卤化物的情况下。[1]不饱和腈可以通过相应的醛与氰基烷基磷酸酯的Wittig反应来合成。[1]上述过时的方法经常产生大量的无机盐作为废物，这从绿色化学的观点来看是不希望的。[2]因此，开发新的环境友好型程序非常重要。过渡金属催化醛肟或酰胺在中性条件下的脱水反应是一种很好的绿色腈合成方法。[3]近年来，催化脱水反应的优良实例不断被报道。[3]合成腈的另一种方法是直接从醇和氨进行氧化反应。[4，5]直接合成非常困难，并且报道的方法需要使用化学计量的反应性氧化剂和试剂，例如I2、[4a，B] 1，3-二碘-5，5-二甲基乙内酰脲（DIH）、[4a，c] NiSO 4/K2 S2 O 8/NaOH、[4d] MnO 2/MgSO 4、[4 e]和（Bu 4 N）2S 2 O 8/Cu（HCO 2）2/Ni（HCO 2）2/KOH。[4f]因此，如果可以实现使用分子氧（或空气）作为唯一氧化剂直接由醇和氨催化氧化合成腈，则由于其高原子效率和缺乏有毒废物（理论上，仅形成水作为副产物[Eq.我们最近报道了醇[6a，B]和胺[6a，c]的有效有氧氧化脱氢和胺的催化氧化成酰胺[6d]，其由容易制备的负载型氢氧化钌催化剂Ru（OH）x/Al 2 O 3催化。在我们的研究过程中，我们发现，在负载型氢氧化钌催化剂的存在下，可以实现直接由醇和氨液相有氧氧化合成腈。[7]各种芳族和杂芳族伯醇可以高产率转化为相应的腈，并且观察到的催化是多相的。[八]《中国日报》
Nitriles are a very important class of compounds in chemistry as well as biology, and they are widely used in the production of pharmaceuticals, agricultural chemicals, and fine chemicals.[1] Aromatic nitriles can be synthesized by the Sandmeyer reaction and gas-phase ammoxidation in laboratories and industry, respectively.[1] The nucleophilic substitution of alkyl halides with a stoichiometric amount of hazardous inorganic cyanides is a general procedure for the synthesis of alkylnitriles and is frequently accompanied by the elimination of hydrogen halides especially in the case of bulky alkyl halides.[1] Unsaturated nitriles can be synthesized by the Wittig reaction of the corresponding aldehydes with cyanoalkyl phosphates.[1] The above antiquated procedures often produce large amounts of inorganic salts as waste, which is not desirable from the standpoint of green chemistry.[2] Therefore, the development of new environmentally friendly procedures is very important. The transition-metal-catalyzed dehydration of aldoximes or amides under neutral conditions is a good candidate for green nitrile synthesis.[3] Recently, excellent examples for the catalytic dehydration have been reported.[3] An alternative approach to the synthesis of nitriles is the oxidative reaction directly from alcohols and ammonia.[4, 5] The direct synthesis is very difficult, and reported procedures require the use of stoichiometric amounts of reactive oxidants and reagents such as I2,[4a, b] 1, 3-diiodo-5, 5-dimethylhydantoin (DIH),[4a, c] NiSO4/K2S2O8/NaOH,[4d] MnO2/MgSO4,[4e] and (Bu4N) 2S2O8/Cu (HCO2) 2/Ni (HCO2) 2/KOH.[4f] Therefore, if the catalytic oxidative synthesis of nitriles directly from alcohols and ammonia using molecular oxygen (or air) as the sole oxidant could be realized, it would be a desirable transformation because of its high atom efficiency and the lack of toxic waste (theoretically, only water is formed as a byproduct [Eq.(1)].We have recently reported the efficient aerobic oxidative dehydrogenation of alcohols [6a, b] and amines,[6a, c] and the catalytic oxygenation of amines to amides [6d] catalyzed by an easily prepared supported ruthenium hydroxide catalyst, Ru (OH) x/Al2O3. During the course of our investigations, we discovered that the liquid-phase aerobic oxidative synthesis of nitriles directly from alcohols and ammonia can be realized in the presence of the supported ruthenium hydroxide catalyst.[7] Various kinds of aromatic and heteroaromatic primary alcohols can be converted into the corresponding nitriles in high to excellent yields, and the observed catalysis is heterogeneous.[8]