Aromaticity and Unsaturation of Metalladichalcogenolene Rings

[CPCO(S_2C_2X，Y)]-型配合物中的金属卤代烯环是非常独特的具有芳香性和不饱和性的共轭金属螯合环。芳香性是亲电或自由基反应中取代反应的根源，而环的不饱和性导致了加成反应。本研究的目的是阐明准芳香共轭金属螯合环的独特性质。在本工作中，我们观察到了以下有趣的结果：(1)芳香性反应：[CpCO(S_2C_2Ph，H)](1)与AIBN反应导致钴二硫烯环或CP环上的1-氰基-1-甲基乙基取代氢。通常情况下，钴二硫烯环对自由基取代反应更活跃。然而，14族元素氢化物的加入促进了CP环(3)的反应，抑制了钴二硫烯环(2)的反应。…的区域选择性(比/3：2)Cp环上的取代顺序为：Bu_3SnH(100：0)&GT；Bu_3GeH(75：25)&GT；Bu_3SiH(36：)&GT；Bu_4Sn(32：68)&GT；无添加剂(19：81)。在二硫代钴配合物[CPCO(S_2C_2Ph，H)]与二(苯并[d]-1，3-噻唑-2-基)二硫化物在苯中回流的反应中，钴二硫杂环和乙腈回流时选择性地发生硫心自由基的取代，(2)不饱和反应：叠氮化物与[CPCO(S_2C_2Z_2)](Z=CoOMe)反应生成Co和S之间的亚胺桥联化合物(两组分加合物)。PPh_3的2个等价物与对甲苯磺酰亚胺桥联的络合物发生了有趣的反应，而亚烷基桥联的络合物则没有观察到。PPh_3与Co在室温下配位，使Co-N键断裂形成叶立德络合物(三组分加合物)。在苯中加热80℃时，磺酰亚胺基团从S迁移到CP环上。此外，在过量的PPh_3与亚胺桥联络合物的反应中，NTS和PPh_3基团从钴二硫烯环向CP环发生了双重迁移，芳香性和不饱和性的共存是这种准芳香环独特的反应性或电化学行为的根源。较少

The metalladichalcogenolene rings in [CpCo(S_2C_2X, Y)]-type complexes are very unique conjugated metal chelate rings which exhibit both aromaticity and unsaturation. Aromaticity is the origin of substitution reactions in electrophilic or radical mechanism, while the unsaturated character of the ring causes addition reactions. The purpose of this study is to elucidate the unique features of quasi-aromatic conjugated metal chelate rings. In this work, we observed the following interesting results.(1) Reactions due to aromaticity : The reaction of [CpCo(S_2C_2Ph, H)](1) with AIBN brings about the substitution of hydrogens with 1-cyano-1-methylethyl group either in the cobaltadithiolene ring or in the Cp ring. Normally the cobaltadithiolene ring is more reactive for the radical substitution. However, the addition of group 14 element hydride compounds promotes the reaction in the Cp ring (3) and inhibits the reaction in the cobaltadithiolene ring (2). The regio-selectivity (ratio/3 : 2) fo … More r the substitution in Cp ring changed in order of Bu_3SnH (100 : 0)>Bu_3GeH (75 : 25)>Bu_3SiH (36 : 64)>Bu_4Sn (32 : 68)>no additive (19 : 81).In the reaction of the cobaltadithiolene complex [CpCo(S_2C_2Ph, H)] with bis (benzo[d]-1,3-thiazol-2-yl) disulfide under refluxing in benzene, substitutions by sulfur-centered radicals occured selectively in the cobaltadithiolene ring and in that under refluxing in acetonitrile, the product by nitrogen-centered radicals or ions was also observed.(2) Reactions due to unsaturation : Azides react with [CpCo(S_2C_2Z_2)](Z=COOMe) to form imido-bridged complexes (2-component adducts) between Co and S.The reaction of 2 equivalents of PPh_3 with the p-tolylsulfonylimido-bridged complex showed an interesting reaction which is not observed for the alkylidene-bridged complex. The coordination of PPh_3 with Co at room temperature causes the Co-N bond cleavaged to give an ylide complex (3-component adduct). Upon heating at 80℃ in benzene, the sulfonylimido group migrates from S to the Cp ring. Further, the double migration of the NTs and PPh_3 groups to tha Cp ring from the cobaltadithiolene ring occured in the reaction of excess PPh_3 with the imido-bridged complex.The coexistence of aromaticity and unsaturation is the origin of unique reactivities or electrochemical behavior of this quasi-aromatic ring. Less