Iodine-Promoted Strategy Of Cyclohexenones Aromatization: A Concise Of Phenols And Aromatic Primary Amines

Molecular iodine has broad transformation ability for functional groups and it is the efficient catalyst for various organic reactions.This paper includes two parts: iodine catalyzes and oxidizes the cyclohexenones aromatization to synthesize the meta-substitution phenols and the Semmler-Wolff reaction promoted by the iodine.Phenolic compounds are the important premise for the synthesis of bioactive molecules,polymers and other fine chemicals.It is relatively easy to synthesize the phenols with ortho-and para-substituents via aromatic substitution chemistry.However,the localization effect of the aromatic substitution makes synthesis of meta-substitution phenols a challenging task.Therefore,we have explored the method of synthesizing meta-substitution phenols regarding cyclohexenones as a substrate.The transformations are initiated with a catalytic amount of molecular iodine as the direct oxidant,while dimethyl sulfoxide is employed as the terminal oxidant.This strategy avoids using the heavy metal catalyst and expensive reagents.Besides,the substrates could be facilely prepared and for a wide range of applications,the oxidative conditions are so mild that the overoxidation of products has not been observe.It is possible to effectively construct the phenols derivatives of meta-substitution with the cheap commercial chemicals under mild conditions.Aromatic amines represent another important organic synthetic intermediate,Ordinary aromatic amine can generally be reduced by aromatic nitro compounds,but substituting the aromatic amines of meta-substitution demands a lengthy synthesis step.Thus,we have explored the Semmler-Wolff reaction promoted by iodine,which transforms the cyclohexenone oximes into aromatic amines of meta-substitution in one step.Compared with the traditional Semmler-Wolff reaction,this approach does not need the strong Br?nsted acid and harsh reaction conditions,it avoids the pre-derivatization of the oximes and the deprotection step of the product.Moreover,there is no need to use precious metal catalyst,the reaction condition is mild,easy to operate.So this the approach has some practical value.