Density Functional Study on [3+2]-Dipolar Cycloaddition Reaction of the N-heterocyclic Carbene Boryl Azide with Olefins

Abstract

The cycloaddition reactions of the N-heterocyclic carbene boryl azide with methyl acrylate, butenone, and hexafluoropropene have been investigated theoretically. Solvent effects on these reactions have been explored by calculation that included a polarizable continuum model (PCM) for the solvent (C6H6). The title reaction could produce 4-and 5-substituted 1,2,3-triazolines, respectively. The reaction systems have the higher chemical reactivity with the low barriers and could be favored. Yet the smaller differences have been found to occur in energetics, and the cycloaddition reactions occur for s-trans conformations over s-cis conformations. The calculations indicated that the cycloaddition reaction of the alkenes have certain regioselectivity.

DFT Investigation of Hydrogen Atom Abstraction from NHC-Boranes by Methyl, Ethyl and Cyanomethyl Radicals—Composition and Correlation Analysis of Kinetic Barriers

“…Stationary points were fully optimized using the B3LYP [ 42 , 43 , 44 ] and Truhlar’s M06-2X [ 45 ] functionals with the McLean–Chandler 6-311G basis set [ 46 ], which has polarization and diffusion functions on hydrogen and heavier second-row atoms (i.e., 6-311++G(d,p)). The two functionals were selected based on available reports [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ] and our tests. The theoretical methods used often in the available computations of NHC-boranes, involving H-atom abstraction, addition, cyclization and complexation reactions, are B3LYP [ 47 , 48 , 49 , 50 , 51 ] and M06-2X [ 52 , 53 , 54 , 55 ].…”

“…The two functionals were selected based on available reports [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ] and our tests. The theoretical methods used often in the available computations of NHC-boranes, involving H-atom abstraction, addition, cyclization and complexation reactions, are B3LYP [ 47 , 48 , 49 , 50 , 51 ] and M06-2X [ 52 , 53 , 54 , 55 ]. The M06-2X functional, a high-nonlocality functional with double the amount of nonlocal exchange (2X), was recommended for use in main-group thermochemistry, thermodynamic kinetics, noncovalent interactions and so forth.…”