Research On Photocatalytic Trifluoromethylation And Iodination Of Nitrogen-heterocyclic Carbene

Trifluoromethyl exists in many molecules used in pesticides and materials,such as agricultural chemicals(pesticides,fungicides,herbicides),so trifluoromethylation has a wide range of research value and application prospects.Over the years,great progress has been made in visible light and noble metal catalyzed trifluoromethyl reaction.However,the catalysts used in this kind of reaction are expensive and the reaction time is relatively long.Therefore,it is of extensive research value to explore a new method with low price and more efficient reaction.Iodine compounds are widely used and studied in drug synthesis,contrast agents and radioactive labeling.Therefore,the development of simple synthetic methods of iodine compounds has important research value.Using the synergy of N-heterocyclic carbenes(NHCs)and photochemistry to find new catalytic modes,which provides a new idea for traditional methods,has attracted people's interest.In view of the above research status,the methods of trifluoromethylation and iodization catalyzed by N-Heterocyclic Carbene and photocatalysis were developed in this paper.Topic 1: a new way of trifluoromethylation Using N-Heterocyclic Carbene and photocatalysis was developed,and the direct trifluoromethylation of n-alkoxypyridine salt derivatives was described.Compared with the classical trifluoromethylation reaction,the NHCs catalyst used in this paper is cheap and easy to obtain.The innovations of this research scheme are as follows: 1)it provides a new reaction strategy for the introduction of trifluoromethyl groups and enriches the trifluoromethylation reaction.2)The reaction time is shortened and the reaction conditions are mild.3)For the first time,N-Heterocyclic Carbene and photocatalysis were used to catalyze trifluoromethylation,which provided a new reaction path.Topic 2: a heterogeneous metal organic framework(MOF)Catalyst Containing N-Heterocyclic Carbene was designed and synthesized,and applied to iodization and trifluoromethylation.MOF with hexahedral structure was synthesized by using tetracarboxylic acid NHCs as ligand and metal zinc as node.The innovations of this research scheme are as follows: 1)a metal organic framework material containing NHCs was synthesized and used in organic photoreaction.2)Using the cavity of MOF and N-Heterocyclic Carbene catalyst as organic ligand,the reaction activity was improved by increasing the reaction concentration.3)This study provides a new reaction method for the photoreaction of organic synthesis.