Ghorpade Prashant Vasantrao, Pethsangave Dattatray Appasha, Some Surajit, Shankarling Ganapati Subray
Department of Dyestuff Technology , Institute of Chemical Technology , N. P. Marg , Matunga, Mumbai 400019 , India.
J Org Chem. 2018 Jul 20;83(14):7388-7397. doi: 10.1021/acs.joc.8b00188. Epub 2018 May 2.
The mildly acidic and oxidative nature of graphene oxide, with its large surface area available for catalytic activity, has been explored in aromatic nuclear bromination chemistry for the first time. The versatile catalytic activity of graphene oxide (GO) has been used to selectively and rapidly brominate anilines and phenols in water. The best results were obtained at ambient temperatures using molecular bromine in a protocol promoted by oxidative bromination catalyzed by GO; these transformations proceeded with 100% atom economy with respect to bromine and high selectivities for the tribromoanilines and -phenols. Reduced graphene oxide (r-GO) was observed to form after the second recycle (third use) of GO. This technique is also effective with N-bromosuccinimide (NBS) as the brominating reagent. In the case of NBS, reactions were instantaneous and the GO displayed excellent recyclability without any loss of activity over several cycles.
氧化石墨烯具有轻度酸性和氧化性，其大表面积可用于催化活性，首次在芳核溴化化学中得到探索。氧化石墨烯（GO）的多功能催化活性已被用于在水中选择性且快速地溴化苯胺和苯酚。在由GO催化的氧化溴化促进的方案中，使用分子溴在环境温度下获得了最佳结果；这些转化相对于溴具有100%的原子经济性，并且对三溴苯胺和三溴苯酚具有高选择性。观察到在GO第二次循环使用（第三次使用）后形成了还原氧化石墨烯（r-GO）。该技术以N-溴代琥珀酰亚胺（NBS）作为溴化试剂时也有效。在使用NBS的情况下，反应是瞬时的，并且GO在几个循环中显示出优异的可回收性，活性没有任何损失。
