We are currently upgrading the certain systems that support this website.  You may experience some functionality loss, though we expect the site to be fully functional by 9:00PM CT (US), February 24th.

We apologize for any inconvenience and appreciate your patience during this improvement process.Please note that you still have telephone and email access to our local offices. We apologize for any inconvenience.

Photoredox Iridium Catalyst for Single Electron Transfer (SET) Cross-Coupling


C(sp2)- and C(sp)-hybridized coupling reactions are established catalytic approaches. However, multi-step C(sp3)- and C(sp2)-coupling reactions of boronic acids and related derivatives are still limited by ineffective two-electron transmetalation reactions. These conventional protocols exhibit reactivity profiles related to heterocyclic C-B bond strengths, thereby greatly impeding progress toward efficient cross-coupling of C(sp3)-hybridized alkylboron nucleophiles.

Recently, a series of efficient, single-election transmetalation methods have been optimized for alkyl cross-coupling using a dual-catalyst system of nickel (244988) and iridium (804215) catalysts, whereby a potassium organotrifluoroborate is activated for cross-coupling via oxidative fragmentation to an alkyl radical. This mechanistic paradigm allows reactivity to be dictated by homolytic bond strengths, opening a new realm of possibilities in alkylboron cross-coupling. In collaboration with the Gary Molander group, Sigma-Aldrich now offers a novel catalyst for high-yielding SET reactions.




  • Previously unrealistic C(sp3)-coupling reactions are now an efficient reality
  • Reaction is performed at room temperature
  • Possibilities for asymmetric coupling
  • Reductive elimination using a chiral nickel catalyst allows stereoconvergent synthesis from racemic organotrifluoroborate substrates

Special thanks to Mr. John Tellis and Prof. Gary Molander for contributing this technology spotlight.


Related Links