Study On Electrochemical Hydroxymethylation And Selenide Reaction Of Aryl-terminal Alkynes

Alkynyl compounds are widely present in the core framework of natural products and active drug molecules,which are important synthetic building blocks in organic synthesis.Therefore,it is necessary to develop highly selective strategies for introducing alkynyl fragments.Aryl propargyl alcohols compounds are important building block for the synthesis of different heterocyclic skeletons,such as indenes derivatives,quinoline derivatives,dihydroquinolone derivatives,2,5-dihydrofuran derivatives,oxazole derivatives and piperazine derivatives,etc.However,organic selenium compounds have the characteristics of unique biochemical properties and significant diversity of activities,which have broad prospects for pharmaceutical research and development,and their synthesis research is of great significance.Therefore,taking terminal alkyne as the research object,exploring and constructing new synthetic methods of alkynyl alcohol and alkynyl selenoether compounds have practical application value.This program focuses on exploring new methods for simple and gentle synthesis of aryl propargyl alcohol and aryl alkyne selenide compounds using electrochemical methods and starting with aryl-terminal alkynes.Under electrochemical conditions,using aryl-terminal alkynes as raw materials,N,N,N-trimethylanilinium trifluoromethanesulfonate as electrolyte,sodium carbonate as base,N,N-Dimethylacetamide was used as the solvent,and a small amount of water was added to successfully expand 29 kinds of aryl propargyl alcohol compounds at room temperature,and the yield was between 36%-95%.The mechanism was verified by free radical trapping experiments and isotope labeling experiments,which proved that the reaction system generate methyl radicals and the oxygen atoms in hydroxymethyl were derived from oxygen in water under electrochemical conditions.The electrochemical synthesis method does not require strong base and metal catalysis,and can synthesize aryl propargyl alcohol compounds under mild conditions.At room temperature,using aryl-terminal alkynes as raw materials,tetrabutylammonium hexafluorophosphate as electrolyte,adding diselenides,cesium carbonate as base,and N,N-dimethylacetamide as solvent,it was successfully synthesized by electrochemical method 12 kinds of aryl alkyne selenoether compounds,the highest yield reached 96%.The electrochemical synthesis method does not require metal catalysis,and can efficiently prepare aryl alkyne selenide compounds under mild conditions.