The Difference in Ir-Catalyzed C(sp)-H and C(sp)-H Bond Activation Assisted by a Directing Group: Cyclometalation via - or -Chelation?

Iridium-catalyzed C-H borylation of aromatic and aliphatic hydrocarbons assisted by a directing group was theoretically investigated. Density functional theory (DFT) calculations revealed both Ir-catalyzed C(sp)-H and C(sp)-H borylations via an Ir/Ir catalytic cycle, where the tetra-coordinated (C, N)Ir(Bpin) complex with two vacant sites is an active species. Dramatically, the orientation of cyclometalation for C(sp)-H bond activation assisted by a directing group is different from the C(sp)-H one.

Theoretical Insight into the Multiple Roles of LiHMDS in Pd-Catalyzed Borylation of Fluorobenzene.

Pd-catalyzed borylation of fluorobenzene was theoretically studied. DFT calculations revealed that the reaction occurs through an unprecedented 3 + 6-membered ring transition state, in which one LiHMDS (HMDS = hexamethyldisilazane) acts as a ligand and another LiHMDS is essential to provide Li···N and Li···F interactions, overcoming the large destabilization of the strong phenyl-F bond distortion. The characteristic feature of LiHMDS was elucidated by comparing it with HMDS and NaHMDS analogues.

Electronic Structures and Unusual Chemical Bonding in Actinyl Peroxide Dimers [AnO] and [(AnO)(12-crown-4 ether)] (An = U, Np, and Pu).

As known, actinyl peroxides play important roles in environmental transport of actinides, and they have strategic importance in the application of nuclear industry. Compared to the most studied uranyl peroxides, the studies of transuranic counterparts are still few, and more information about these species is needed. In this work, experimentally inspired actinyl peroxide dimers ([AnO], An = U, Np, and Pu) have been studied and analyzed by using density functional theory and multireference wave function methods.