I₂-catalyzed Direct Synthesis Of 2-substituted Quinoxaline From Aromatic Ketones And 1,2 Diamine

This paper mainly reported the molecular iodine as the catalyst in organic synthesis reaction.Iodine as the catalyst effectivly catalyzed numerous reactions,and the reaction conditions are mild,simple,high yield.At the same time,quinoxaline and ?-hydroxy aryl methyl ketone skeleton is the core of many natural products,with widely present in the natural products and drug molecules.Based on this,the paper mainly studied direct synthesis of quinoxaline and ?-hydroxy aromatic ethanone by iodine catalysis.The paper consists of three parts:Chapter ?,main application of iodine in organic synthesis are reviewed,including:iodination of organic compounds;protection-deprotection of functional groups;oxidation of alcohols and aldehydes to esters,nitriles,amides;C-C/C-N/C-O/C-S bond formation and break,heterocyclic compound synthesis.Chapter ?,on the basis of our group preliminary work of ?-iodination,aryl methyl ketone compounds as the simple and easy get starting material transforms alpha iodine aromatic ethyl ketone intermediate which continues to react with 1,2-diamine through cyclization-oxidation to get quinoxaline compounds without separation and purification.At the same time,we put forward assumptions on the mechanism of the reaction,the target compounds through the 1HNMR,13CNMR,IR and HRMS representation of the target compounds ?-3c is also confirmed by the crystal structure.Chapter ?,the methods of synthesis of alpha-hydroxy aryl methyl ketone was summarized.Then the synthesis of a-hydroxy aryl ethanone was reported by substituted aryl ethylene as substrate,TBHP/I2 as oxidant,no metal,room temperature.Wherein the target compound ?-60c was verified by crystal structure.