Ramos B., Castriciones E.V.
University of the Philippines, PH
Keywords: density functional theory, insertion/addition reaction, organotitanium complex, reaction mechanism, semi- empirical quantum chemistry
We present our preliminary results on the quantum chemical studies carried out to elucidate the diastereoselective insertion-addition reaction of a chiral titanium(IV)-Schiff base-benzyl complex (I) with hydroxyketones (II) to form the diastereoselective insertion product (III) in Figure 1. Calculations were performed within the semiempirical methods GFN2-xTB and PM6 as well as with B3LYP in implicit toluene. Possible reactivity sites were examined by investigating the frontier molecular orbitals and the condensed Fukui functions of the reactants. Based on these reactivity indicators and on a previously proposed mechanism for the reaction, a possible reaction pathway is rationalised. For all levels of theory considered in this work, the transition state leading to the insertion of the hydroxyketone and migration of the benzyl moiety to the ketone, appears to be the rate-determining step for the reaction. The semiempirical methods resulted in a lower activation energy for the transition point compared with B3LYP.
Journal: TechConnect Briefs
Volume: TechConnect Briefs 2021
Published: October 18, 2021
Pages: 101 - 104
Industry sector: Advanced Materials & Manufacturing
Topics: Advanced Materials for Engineering Applications, Materials Characterization & Imaging
ISBN: 978-0-578-99550-2