Mechanism and Origins of Chemo- and Stereoselectivities of Aryl Iodide-Catalyzed Asymmetric Difluorinations of β-Substituted Styrenes.

ABSTRACT: The mechanism of the aryl iodide-catalyzed asymmetric migratory geminal difluorination of β-substituted styrenes ( Banik et al. Science 2016, 353, 51 ) has been explored with density functional theory computations. The computed mechanism consists of (a) activation of iodoarene difluoride (ArIF₂), (b) enantiodetermining 1,2-fluoroiodination, (c) bridging phenonium ion formation via S_N2 reductive displacement, and (d) regioselective fluoride addition. According to the computational model, the ArIF₂ intermediate is stabilized through halogen-π interactions between the electron-deficient iodine(III) center and the benzylic substituents at the catalyst stereogenic centers. Interactions with the catalyst ester carbonyl groups (I(III)⁺···O) are not obse

SUBMITTER: Zhou B 

PROVIDER: S-EPMC6261351 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature