A molecular electron density theory study of the chemo- and regioselective [3+2] cycloaddition reactions between trifluoroacetonitrile N-oxide and thioketones

作者：Emamian Saeedreza^*; Lu Tian; Domingo Luis R; Saremi Leily Heidarpoor; Rios Gutierrez Mar

来源：Chemical Physics, 2018, 501: 128-137.

DOI：10.1016/j.chemphys.2017.12.019

• [3+2] cycloaddition reactions
• Nitrile N-oxides
• Chemoselectivity
• Regioselectivity
• ELF topological analysis
• Molecular Electron Density Theory (MEDT)

The [3 + 2] cycloaddition (32CA) reaction between trifluoroacetonitrile N-oxide (NO 7) and 2,2,4,4-tetramethyl-3-thioxocyclobutan-1-one (THK 12) as well as the self-dimerization of NO 7 as a competitive pathway were studied within the Molecular Electron Density Theory (MEDT) using several DFT functionals together with def2-TZVP basis set. Taking CCSD(T)/TZVP activation energies as reference, among the employed functionals, just the B2PLYP-D3(BJ) one is able to portray complete predominance of 32CA reaction over self-dimerization process in excellent agreement with the experimental outcomes. Analysis of the global reactivity indices permits to characterize NO 7 and THK 12 as a strong electrophile and a strong nucleophile, respectively, while analysis of the Parr functions allows explaining the chemo- and regioselectivity observed experimentally. The electron localization function (ELF) analysis of several points along the IRC profile associated with the energetically most favorable reaction channel permits to establish a non-concerted two-stage one-step molecular mechanism for this polar pmr-type 32CA reaction.

• 出版日期2018-2-14