Theoretical Studies Of The Mechanism Of The Au-Catalyzed Alkynes Nitrogenation And Ir-Catalyzed Aromatic C-C Bond Activation

Carbon-carbon bond activation of transition metal-catalyzed hydrocarbons and subsequent functionalization into complex product structures are an attractive strategy.In recent decades,scientists have done a lot of experimental research on this piece,but there are few theoretical studies on this piece.Therefore,the reaction mechanism of such reactions is explored to provide more effective guidance for a series of follow-up reactions It makes a lot of sense.In this paper,the mechanism of nitrocarburizing catalyzed by transition metal gold and the selective cleavage of iridium-catalyzed aromatic C-C bond were investigated by using density functional theory?DFT?/M06/B3LYP method.In the third chapter,the mechanism of nitridation of alkyne and azide?TMSN₃?catalyzed by transition metal gold is mainly studied.The main discussion is that the acidity of methanesulfonic acid?CH₃SO₃H?and triflic acid?CF₃SO₃H?determines which of the two reaction pathways follows.For end-alkynes,methanesulfonic acid favors the formation of a carbamide?urea?compound,while triflic acid prefers to the aminotetrazole compound.It is chemicallyselective.For terminal alkynes,methanesulfonicacid?CH₃SO₃H?and trifluoromethanesulfonic acid?CF₃SO₃H?preferentially form carbamides?urea?compounds.In the fourth chapter,the mechanism of selective C-C bond cleavage of aromatic compounds catalyzed by transition metal iridium was studied.In the present study,we aimed to use DFT calculations to elucidate the mechanism and regioselectivity of the reaction.Several possible reaction pathways,one,two,three and four iridium pathways,are calculated and compared.The results of these calculations show that iridium insertion has the lowest energy in a four-iridium path that occurs in a stepwise manner.Analysis using m-xylene as a substrate shows that steric hindrance plays a key role in determining regioselectivity.The electronic factor well explains that benzene gives the highest potential barrier,whereas mesitylene gives the lowest potential barrier.