Theoretical Study on Hetero-Diels-Alder Reaction of Butadiene with Benzaldehyde Catalyzed by Chiral InIII Complexes

摘要: The mechanism of the hetero-Diels-Alder reaction butadiene with benzaldehyde catalyzed by chiral N,N'-dioxide/ In(OTf) 3 complexes was studied theoretically using density functional theory (DFT) and model system. computational results indicate that proceeded through a concerted via highly zwitterionic transition state. lowest energy barrier 11.8 kJ mol -1 , which is 63.0 kJmol lower than uncatalyzed re-action. endo approach advantageous over exo approach, because transitions states suffer from more steric hindrance as result interactions among substrates, trifluoromethanesulfonic group R 4 groups ligand. (S) configuration observed predominantly (R) form, there no distinguishable repulsion between amino side or Besides, terminal hydrogen atoms oxygen make structure stable. Thus, experimental were explained well calculation N,N'-dioxide/In-(OTf) complex at molecular level.