Pan, Xiangcheng Lacôte, Emmanuel Lalevée, Jacques Curran, Dennis P. Polarity Reversal Catalysis in Radical Reductions of Halides by N-Heterocyclic Carbene Boranes Otherwise sluggish or completely ineffective radical reductions of alkyl and aryl halides by N-heterocyclic carbene boranes (NHC-boranes) are catalyzed by thiols. Reductions and reductive cyclizations with readily available 1,3-dimethylimidazol-2-ylidene borane and a water-soluble triazole relative are catalyzed by thiophenol and <i>tert</i>-dodecanethiol [C<sub>9</sub>H<sub>19</sub>C­(CH<sub>3</sub>)<sub>2</sub>SH]. Rate constants for reaction of the phenylthiyl (PhS•) radical with two NHC-boranes have been measured to be ∼10<sup>8</sup> M<sup>–1</sup> s<sup>–1</sup> by laser flash photolysis experiments. An analysis of the available evidence suggests the operation of polarity reversal catalysis. thiophenol;evidence;C 9H Rate constants;borane;PhS;dimethylimidazol;reductive cyclizations;Polarity Reversal Catalysis;aryl halides;thiol;polarity reversal catalysis;Carbene;BoranesOtherwise;triazole;phenylthiyl;laser flash photolysis experiments;carbene;alkyl;analysis;Radical Reductions;Halide 2012-03-28
    https://acs.figshare.com/articles/journal_contribution/Polarity_Reversal_Catalysis_in_Radical_Reductions_of_Halides_by_N_Heterocyclic_Carbene_Boranes/2536612
10.1021/ja300416f.s002