Direct Transformation Of Carbonyl Compounds And Aromatic Compounds Via Electrochemical Method

The transformation of carbonyl compounds and aromatic compounds have drawn considerate interests in current organic synthesis.Since the transformation can introduce special property by incorporation of different functional groups,which are widely used in developments of drugs,materials and pesticides.Although tremendous achievements have gained in the field of the transformation of carbonyl compounds and aromatic compounds,many challenges remain unsolved,such as the synthesis costs,products pollution and the reaction post-treatment.To meet the requirements of green chemistry,organic electrochemical synthesis was utilized as a suitable strategy to transform carbonyl compounds and aromatic compounds with less pollution in simple operation conditions.In this thesis,we have successfully applied electrochemical synthetic tools in the transformation of carbonyl compounds and aromatic compounds,as summarized below:1.Initiator-free electrochemical trifluoromethylsilylation and cyanosilylation of aldehydes were developed in an undivided cell.DFT calculations reveal that cathode direct interaction with organosilicon compounds can form the anion intermediates,which react with aldehydes to generate concerted anionic complexes,which undergo the intramolecular-CF₃,-CN migration to generate corresponding products with high chemo-selectivity and yields.2.The effect of pore size of nanoporous gold（NPG）on electrochemical reduction of functionalized carbonyl compounds was investigated.The best catalytic performance was obtained by using an NPG with pore size of～30 nm（NPG-M）cathode,possibly due to the high electrochemically active surface area,current density and low solution resistance.Notably,in the presence of diphenylsilane,the NPG-M electrode can selectively reduce p-NBD to corresponding alcohols with TOF up to 232,000 h^-1.3.Electrochemical reduction of aromatic compounds was achieved without the use of alkali metals in an undivided cell.With the glassy carbon（cathode）and the graphite（anode）as pair electrodes,Birch reduction of the benzene derivatives proceed successfully in conductive ethylenediamine solution without the aid of alkali metals.Moreover,the electrochemical reaction tolerates many heteroarenes with high activities.