On the Mechanism of the Copper-Mediated C鈥揝 Bond Formation in the Intramolecular Disproportionation of Imine Disulfides

详细信息    查看全文

• 作者：Tibor Andr谩s Rokob ; Lubom铆r Rul铆拧ek ; Ji艡铆 艩rogl ; 脕gnes R茅v茅sz ; Emilie L. Zins ; Detlef Schr枚der
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：October 17, 2011
• 年：2011
• 卷：50
• 期：20
• 页码：9968-9979
• 全文大小：1236K
• 年卷期：v.50,no.20(October 17, 2011)
• ISSN：1520-510X

文摘

The mechanism of the copper-mediated disproportionation of aromatic imine disulfides to benzothiazoles in the gas phase is investigated by experimental and theoretical methods. Application of infrared multiphoton dissociation and hydrogen/deuterium exchange experiments combined with density functional theory (DFT) calculations of the relevant molecular structures and the associated infrared spectra allows the identification of the observed ionic intermediates. The theoretical investigation of the possible reaction pathways supported by collision-induced dissociation experiments provides a consistent mechanistic picture of the reaction catalyzed by a single copper(I) ion. Activation of the substrate proceeds via homolytic sulfur鈥搒ulfur bond cleavage, yielding metal complexes in the formal +3 oxidation state; carbon鈥搒ulfur coupling and hydrogen-atom transfer complete the transformation to the products. Exploratory studies demonstrate that in the gas phase, the disproportionation of the imine disulfide can also be mediated by other metal ions via different either homo- or heterolytic mechanisms without involving high-valent intermediates.