Forged in iron

Fifty years ago, Kochi reported the iron-catalysed cross-coupling of alkenyl halides and alkyl Grignard reagents. Sparking a cross-coupling revolution, we reflect on the impact of this achievement and the importance of iron in the development of cross-coupling catalysis. In a reaction discovered 50 years ago, a disarmingly simple iron catalyst was shown to couple alkenyl halides to alkyl Grignard reagents. This finding led to a proliferation of catalytic methodologies that today are an indispensable part of our synthetic toolkit.