Radical chain reduction of alkylboron compounds with catechols

J Am Chem Soc. 2011 Apr 20;133(15):5913-20. doi: 10.1021/ja110224d. Epub 2011 Feb 22.


The conversion of alkylboranes to the corresponding alkanes is classically per-formed via protonolysis of alkylboranes. This simple reaction requires the use of severe reaction conditions, that is, treatment with a carboxylic acid at high temperature (>150 °C). We report here a mild radical procedure for the transformation of organoboranes to alkanes. 4-tert-Butylcatechol, a well-established radical inhibitor and antioxidant, is acting as a source of hydrogen atoms. An efficient chain reaction is observed due to the exceptional reactivity of phenoxyl radicals toward alkylboranes. The reaction has been applied to a wide range of organoboron derivatives such as B-alkylcatecholboranes, trialkylboranes, pinacolboronates, and alkylboronic acids. Furthermore, the so far elusive rate constants for the hydrogen transfer between secondary alkyl radical and catechol derivatives have been experimentally determined. Interestingly, they are less than 1 order of magnitude slower than that of tin hydride at 80 °C, making catechols particularly attractive for a wide range of transformations involving C-C bond formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkanes / chemistry
  • Antioxidants / chemistry
  • Boranes / chemistry*
  • Catechols / chemistry*
  • Oxidation-Reduction
  • Phenols / chemistry


  • Alkanes
  • Antioxidants
  • Boranes
  • Catechols
  • Phenols
  • tert-butylcatechol
  • phenoxy radical