摘要/Abstract

氰基化合物是一类具有重要价值的有机物.研究了以丙酮氰醇为反应试剂，以取代的3，5-二甲基-N-α，β-不饱和酰基吡唑为底物时发生在不同位点的两种反应.研究结果表明，芳香取代的3，5-二甲基-N-α，β-不饱和酰基吡唑为底物时，使用不同的碱性催化剂会发生两种不同类型的反应：MgBu₂存在时体系发生Michael加成反应，产物收率最高可达95%；在四甲基胍（TMG）存在时体系发生酰胺的醇解反应，生成β-取代苯基丙烯酸氰醇酯，收率最高达84%.脂肪取代的3，5-二甲基-N-α，β-不饱和酰基吡唑与丙酮氰醇在MgBu₂或TMG存在下均发生Michael加成反应，产率最高为99%.讨论了使用不同碱性催化剂时的反应机理.
关键词: 丙酮氰醇, 3,5-二甲基-N-α,β-不饱和酰基吡唑, Michael加成反应, β-取代苯基丙烯酸氰醇酯
Cyano compounds are a class of organic compounds with great value. Two different kinds of reactions have been reported using acetone cyanohydrin as reagent and substituted 3,5-dimethyl-N-α,β-unsaturated acyl pyrazole as substrate. The reaction pathway depends on the basic catalysts used when aromatic substituted 3,5-dimethyl-N-α,β-unsaturated acyl pyrazole was used as the substrate. Michael addition reaction occurred in the presence of MgBu₂ with the product yield up to 95%, while alcoholysis reaction of amide occurred in the presence of 1,1,3,3-tetramethylguanidine (TMG), producing β-substituted phenyl cyanoacrylates with 84% yield. However, fatty substituted 3, 5-dimethyl-N-α,β-unsaturated acyl pyrazole and acetone cyanohydrin underwent Michael addition reaction in the presence of MgBu₂ or TMG, the product yield was up to 99%. The possible reaction mechanism when using different basic catalysts was discussed.
Key words: acetone cyanohydrin, 3,5-dimethyl-N-α,β-unsaturated acyl pyrazole, Michael addition, β-substituted phenyl cyanoacrylate


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