Rhodium-catalyzed Ortho-phenylation Of Aromatic Carboxylic Acids And Graphene Oxide-catalyzed Iodination Of Aromatics

Biphenyls as one of the basic skeleton have been widely applied in agrochemicals,pharmaceuticals and multifunctional materials.Compared with the traditional methods,direct arylation reaction of aromatics has the advantage of shorting the reaction step,low reaction cost and high atom economy efficiency.Recently,the arylation reactions of aromatics in the presence of directing-group have been developed well.However,these methods suffered from using expensive coupling partner or harsh reaction conditions.Aryl iodides is a kind of important intermediates in organic synthesis and widely presented in pharmaceutically active agents.Conventional synthesis of iodoarenes suffered from multi-step reaction,required strong acid or metal as catalyst.Therefore,the development of efficient synthetic protocols to synthesis aryl iodides is of great significance.The research work is described as follows:1.An efficient and practical strategy for the arylation of simple aromatic acids was developed by using Rh/Cu as catalyst,inexpensive NaBPh4 as aryl-source,and air as the terminal oxidant.The reaction is silver-free,not sensitive to air,operationally simple,and tolerant to various functional groups.This reaction can also be scaled to gram level easily.2.An efficient and practical strategy for the iodination of arenes by the graphene oxide(GO)catalyst has been developed.This reaction were conducted using GO as a metal-free catalyst,and readily available iodine as iodine source.This method has the following advantages such as neutral medium,easy operation,without adding any additives,compactible with air,scalable and tolerates a wide range of functional groups.Additonaly,?-carbonyl hydrogen can also iodinate smoothly.Particularly,the iodination or di-iodination process could be easily controlled by using different reaction conditions.