Reaction Study On Electrochemical Synthesis Of Disubstituted Sulfoxonium Ylides

Sulfur ylides have received extensive attention as an alternative to diazonium compounds.Compared with general sulfur ylides,?-carbonyl sulfoxonium ylides are widely used in halogenation reactions,C-H functionalization,X(N,O,S)-H insertion,etc.due to their unique properties.The use of the disubstituted sulfoxonium ylides is also very special,which can create a chiral center by simple X(N,O,S)-H insertion.However,it is very difficult to synthesize disubstituted sulfoxonium ylides.In recent years,attempts have been made to directly synthesize disubstituted sulfoxonium ylides from?-carbonyl sulfoxonium ylides.Despite this,reports on the synthesis of disubstituted sulfoxonium ylides are still very limited and the products are single.In addition,a method for the electrochemical preparation of disubstituted sulfoxonioum ylides has not yet been reported.In this study,potassium thiocyanate and chlorine sources were used as substituents to replace sulfoxonium ylides,and a new double substituted sulfoxonium ylides was constructed under electrochemistry.Based on the importance of thiocyanate structure and its wide application in drugs and agricultural chemicals;At the same time,thiocyanates are also important intermediates for the preparation of sulfonic acid,sulfur-containing heterocycles,mercaptans,sulfides,thioesters and thiophosphonates;It has been proved that the synthesis of thiocyanate compounds can be completed by using cheap thiocyanate in transition metal catalysis,oxidant oxidation,photocatalysis and electrocatalysis.It is a feasible means to study the introduction of thiocyano into sulfoxonium ylides by electrochemical method to construct a new thiocyanate.In addition,as a common modification group,chlorine group is also widely used in organic synthesis.It can not only realize the construction of carbon carbon bond through a series of coupling reactions,but also realize its different physiological and pharmacological properties by modifying bioactive substances.Therefore,the introduction of chlorine group into sulfoxonium ylides by electrochemistry is also of great significance.Based on the extensive research of electrochemical chlorination,It is also feasible to introduce chlorine group into sulfoxonium ylides by electrochemistry.In this paper,a synthetic method for the preparation of?-thiocyano-?'-carbonyl sulfoxonium ylides was developed using inexpensive and readily available KSCN and?-carbonyl sulfoxonium ylides as raw materials.After some screening of conditions,optimal reaction conditions was determined.The reaction uses acetonitrile and water as a mixed solvent and a constant current of 5 m A for electrolysis.The reaction has the advantages of no transition metal catalysis,short reaction time,and no external electrolyte.In addition,the method also has a good performance in the scope of substrate application.The obtained product was characterized by ~1H NMR,¹³C NMR and HRMS,and the structure of the product was further confirmed by single crystal diffraction analysis.Also,possible mechanism of the reaction was proposed using cyclic voltammetry and control experiments.At the same time,a synthetic method for preparing?-chloro-?'-carbonyl sulfoxonium ylides and its chloride was developed by using Mg Cl₂ and?-carbonyl sulfoxonium ylides as raw materials.