Organocatalytic versus Iron-Assisted β-Boration of Electron-Deficient Olefins

Combo effects: The first example of an iron‐mediated β‐boration of activated olefins is reported. The origin and the benefits of the catalytic activity associated with the presence of iron have been questioned and carefully studied. The iron system has been compared to the organocatalytic β‐boration of α,β‐unsaturated esters, ketones, and imines (see scheme; acac=acetylacetonate, pin=pinacol).