The particular chemical properties of cyclobutenedione and its derivatives make the cyclobutenedione ring system worthy of special attention. In spite of the ring tension characteristic of four-membered carbocyclic systems, the cyclobutenediones (which may formally be regarded as quinones of the extremely unstable cyclobutadiene) exhibit high thermal stability. This fact has favored the broad investigation of the cyclobutenediones. The preparative results of these investigations are summarized in a tripartite review article. I. Synthesis of Cyclobutenedione and its Alkyl, Alkenyl, and Aryl Derivatives II. Reactions of Alkyl-, Alkenyl-, and Arylcyclobutenediones III. Synthesis of Squaric Acid, Benzocyclobutenedione, and Derivatives thereof In the following Part I of the review, the syntheses of cyclobutenediones from open-chain precursors are described. 1. Cyclobutenediones by Photochemical [2+2] Cycloaddition 1.1. Addition of Alkynes to Alkenes 1.2. Cyclodimerization of Olefinic Compounds (Photodimerization) 2. Cyclobutenediones by Thermal [2+2] Cycloaddition 2.1. Addition of Alkynes to Tetrahaloethylenes 2.2. Addition of Alkynes to Ketenes 2.3. Dimerization of Tetrahaloethylenes 2.4. Thermal [2+2] Cycloaddition of Electron-rich to Electron-poor Ethylene Derivatives 2.5. Thermal Intramolecular Cycloaddition of 1,2,4,5-Hexatetraenes 3. Cyclobutenediones by Ring-Enlargement of Cyclopropene Derivatives 3.1. Ring-Enlargement of 3-Alkoxycarbonyl-3-hydroxycyclopropenes 3.2. Ring-Enlargement by Thermal Cycloaddition of Dichlorocarbene to Cyclopropenes 3.3. Thermal Addition of Isocyanides to Cyclopropenones 4. Diphenylcyclobutenedione from Diphenylacetylene and Tetrakis[arylisocyanide]-nickel 5. Cyclobutenediones from Other Cyclobutenediones 5.1. Halo-arylcyclobutenediones 5.2. 2-Substituted 1-Arylcyclobutenediones from Arylhalocyclobutenediones 5.3. Alkyl- and Arylcyclobutenediones from Squaric Acid Derivatives
环丁烯二酮及其衍
生物的特殊
化学性质使得
环丁烯二酮环系统值得特别关注。尽管四元碳环系统具有环张力的特点,但环
丁二酮(可正式视为极不稳定的
环丁二烯的醌)却表现出很高的热稳定性。这一事实促进了对
环丁烯二酮的广泛研究。本文从三个方面总结了这些研究的制备结果。 I. 环
丁二酮及其烷基、烯基和芳基衍
生物的合成 II.烷基、烯基和芳基环
丁二酮的反应 III.quaric Acid、苯并环
丁二酮及其衍
生物的合成 在以下综述的第一部分中,介绍了从开链前体合成环
丁二酮的方法。 1.通过光
化学 [2+2] 环加成法合成
环丁烯二酮 1.1.
炔烃与烯烃的加成 1.2.烯烃化合物的环二聚化(光二聚化) 2.通过热[2+2]环加成法生成
环丁烯二酮 2.1.
炔烃与四卤
乙烯的加成 2.2.
炔烃与烯酮的加成 2.3.四卤
乙烯的二聚反应 2.4.富电子到贫电子
乙烯衍
生物的热[2+2]环加成反应 2.5.1,2,4,5-六四烯的分子内热环加成 3.通过环
丙烯衍
生物的扩环作用生成
环丁烯二酮 3.1.3- 烷氧羰基-3-羟基环
丙烯的扩环 3.2.
二氯甲烷与环
丙烯的热环化扩环 3.3.
异氰酸酯与
环丙烯酮的热加成 4.
二苯基乙炔和四[芳基异
氰酸]-
镍制二苯基环
丁二酮 5.从其他
环丁烯二酮生成
环丁烯二酮 5.1.卤代芳基环
丁二酮 5.2.由芳基卤代
环丁烯二酮生成的 2-取代 1-芳基
环丁烯二酮 5.3.由四季酸衍
生物生成的烷基和芳基环
丁二酮