🚨RADICAL RETHINK: STEREORETENTIVE CROSS COUPLING UNLOCKED🚨 Today in
@ChemRxiv (
chemrxiv.org/engage/chemrxiv…) the first method for stereoretentive radical cross-coupling is disclosed. No fancy ligands or redox needed—just a Ni-diazene twist. 120 years after Gomberg, a new chapter begins.
Quick summary:
Since Gomberg discovered free radicals over 120 years ago and Kochi pioneered radical cross-coupling in the 1970s, this field has surged with interest for linking C(sp3) fragments. Unlike traditional polar methods (e.g., Suzuki), radical cross-coupling excels with saturated systems, offering mild conditions and chemoselectivity to build complex molecules from common fragments. Until now, enantiospecific radical cross-coupling was deemed impossible due to rapid racemization, but today that changes with readily available sulfonylhydrazides and a simple Ni-catalyst. This stereoretentive approach, enabled by a unique Ni-diazene transition state and driven by loss of N2, skips chiral ligands and redox steps, opening new possibilities for synthesis.