Free Radical Isomerizations in Acetylene Bromoboration Reaction.

ABSTRACT: The experimentally motivated question of the acetylene bromoboration mechanism was addressed in order to suggest possible radical isomerization pathways for the syn-adduct. Addition-elimination mechanisms starting with a bromine radical attack at the "bromine end" or the "boron end" of the C=C bond were considered. Dispersion-corrected DFT and MP2 methods with the SMD solvation model were employed using three all-electron bases as well as the ECP28MWB ansatz. The rate-determining, elimination step had a higher activation energy (12 kcal mol-1) in case of the "bromine end" attack due to intermediate stabilization at both the MP2 and DFT levels. In case of the "boron end" attack, two modes of C-C bond rotation were followed and striking differences in MP2 vs. DFT potential energy surfaces we

SUBMITTER: Semrad H 

PROVIDER: S-EPMC8123272 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature