Anion-Initiated Trifluoromethylation by TMSCF₃: Deconvolution of the Siliconate-Carbanion Dichotomy by Stopped-Flow NMR/IR.

ABSTRACT: The mechanism of CF₃ transfer from R₃SiCF₃ (R = Me, Et, iPr) to ketones and aldehydes, initiated by M⁺X^- (<0.004 to 10 mol %), has been investigated by analysis of kinetics (variable-ratio stopped-flow NMR and IR), ¹³C/²H KIEs, LFER, addition of ligands (18-c-6, crypt-222), and density functional theory calculations. The kinetics, reaction orders, and selectivity vary substantially with reagent (R₃SiCF₃) and initiator (M⁺X^-). Traces of exogenous inhibitors present in the R₃SiCF₃ reagents, which vary substantially in proportion and identity between batches and suppliers, also affect the kinetics. Some reactions are complete in milliseconds, others ta

SUBMITTER: Johnston CP 

PROVIDER: S-EPMC6133236 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature