Theoretical Design of a Catalyst with Both High Activity and Selectivity in C–H Borylation

Abstract

Improving both the activity and selectivity of the C−H borylation reaction is currently a hot research topic but also a challenge. In this regard, we suggest a multistrategy combining directing group, coordination unsaturated metal center, and cationic character. Based on Reek's catalyst, we designed a new unsaturated cationic catalyst (1) featuring a directing group for C−H borylation. The calculated free energy barrier of C−H activation is only 7.2 kcal/mol, indicating that the cationic catalyst has higher activity than the original neutral catalyst in this process. Moreover, the comparison suggests that the ortho-C−H borylation pathway is more favorable than the meta and para pathways. The catalyst deconstructions are further performed and prove that the ortho-selectivity is attributed to hydrogen-bonding interactions between the directing group and the substrate, although the ortho site is sterically and electronically unfavorable.

Hydroboration of CO2 to Methyl Boronate Catalyzed by a Manganese Pincer Complex: Insights into the Reaction Mechanism and Ligand Effect

“…On the basis of our previous computational studies catalyzed by TM complexes, − all geometry optimizations in this paper were carried out at B3LYP-D3/BS-I level using Gaussian 09 program. , Other DFT functionals were tested, but no qualitatively different results were obtained (see Table S1 in the Supporting Information). BS-I denotes that the Mn center adopted the LANL2DZ basis set based on the effective nuclear potential energy approximation (ECP), and for other nonmetal atoms, we applied the Pople’s 2-zeta 6-31G­(d) all-electron basis sets .…”

Acceleration Effect of Bases on Mn Pincer Complex-Catalyzed CO2 Hydroboration

“…In accordance with our previous theoretical studies on boration reactions, ,− all computations in this study were carried out by the DFT method with the ωB97X-D functional using the Gaussian 09 program . Geometries were optimized in a toluene solution using the basis set system BS-I, where Stuttgart/Dresden’s pseudopotential SDD basis set was employed for the Mn atom and the 6-311G­(2d,p) basis set was used for all other atoms. − Harmonic frequency analysis was subsequently performed to verify the optimized geometries to be minima (no imaginary frequency) or transition states (TSs, having unique one imaginary frequency).…”

Density Functional Theory Study on the H2-Acceptorless Dehydrogenative Boration of Alkenes Catalyzed by a Zirconium Complex

“…If not specified, all energies described in the following parts are free energy relative to complex 1 . The NBO analyses were performed using NBO7.0, and visual molecular dynamics, Muliwfn, and CYLview were also used in the orbital analyses and the presentation of geometric structures of stationary points. − The computational and analytical methods have shown some reliability in previous theoretical studies. − …”