Elucidating the mechanism and reactivity of the reaction between the donor–acceptor–acceptor 1,3-bisdiazo compound and cinnamyl alcohol catalyzed by Rh2(OAc)4: a DFT study

Abstract

Diazo compounds have an important role to play in organic synthesis. More theoretical and experimental studies focus on mono-diazo compound but few do so on bi-diazo compounds. Here, the mechanism and reactivity of a donor–acceptor–acceptor 1,3-bisdiazo compound in the reaction with cinnamyl alcohol catalyzed by Rh₂(OAc)₄ are explored by DFT calculations at the M06-D3/SMD/BS2//B3LYP-D3/BS1 level. For this bi-diazo compound, the computational results supported by the natural bond orbital (NBO), frontier molecular orbital (FMO), and atom in molecule (AIM) analyses indicate that the activity of the diazo group with the donor group is more active than that with only the acceptor group. Additionally, the stability of metal carbenoids with the donor substituent group is also higher than the ones without. Meanwhile, the favored mechanistic pathways for the title reaction show that the expected product could not be obtained under the experimental conditions. The influences of experimental conditions on the reaction are explained well in this paper. This study provides details of bisdiazo compounds through all kinds of computational analyses for the first time and hopes to contribute useful information to further experiments.