coupling between halides and aldehydes is a chromium-induced redox
reaction. A key advantage is the high chemoselectivity toward aldehydes.
A disadvantage is the use of excess toxic chromium salts.
Newer methods allow the use of catalytic amounts chromium(II), which is regenerated by reduction with manganese or via electrochemical reduction.
Mechanism of the Nozaki-Hiyama-Kishi Coupling
A Highly Enantioselective Catalyst for the Asymmetric Nozaki-Hiyama-Kishi Reaction of Allylic and Vinylic Halides
A. Berkessel, D. Menche, C. A. Sklorz, M. Schroeder, I. Paterson, Angew. Chem. Int. Ed., 2003, 42, 1032-1035.
Stereochemical Diversity in Chiral Ligand Design: Discovery and Optimization of Catalysts for the Enantioselective Addition of Allylic Halides to Aldehydes
J.-Y. Lee, J. J. Miller, S. S: Hamilton, M. S. Sigman, Org. Lett., 2005, 7, 1837-1839.