Chan-Lam Coupling

This reaction allows aryl carbon-heteroatom bond formation via an oxidative coupling of arylboronic acids, stannanes or siloxanes with N-H or O-H containing compounds in air. Substrates include phenols, amines, anilines, amides, imides, ureas, carbamates, and sulfonamides. The reaction is induced by a stoichiometric amount of copper(II) or a catalytic amount of copper catalyst which is reoxidized by atmospheric oxygen.

The Chan-Lam Coupling may be conducted at room temperature in air, which gives it a certain advantage over the  Buchwald-Hartwig Cross Coupling.

---

Mechanism

The reaction with a stoichiometric amount of copper(II) is also facilitated by oxygen, because reductive elimination from a copper(III) species is faster.

---

Recent Literature

Ligand- and Base-Free Copper(II)-Catalyzed C-N Bond Formation: Cross-Coupling Reactions of Organoboron Compounds with Aliphatic Amines and Anilines
T. D. Quach, R. A. Batey, Org. Lett., 2003, 5, 4397-4400.

Copper(II)-Catalyzed Ether Synthesis from Aliphatic Alcohols and Potassium Organotrifluoroborate Salts
T. D. Quach, R. A. Batey, Org. Lett., 2003, 5, 1381-1384.

An Efficient Base-Free N-Arylation of Imidazoles and Amines with Arylboronic Acids Using Copper-Exchanged Fluorapatite
M. L. Kantam, G. T. Venkanna, C. Sridhar, B. Sreedhar, B. M. Choudary, J. Org. Chem., 2006, 71, 9522-9524.

Synthesis of Diaryl Ethers through the Copper-Promoted Arylation of Phenols with Arylboronic Acids. An Expedient Synthesis of Thyroxine
D. A. Evans, J. L. Katz, T. R. West, Tetrahedron Letters, 1998, 39, 2937-2940.

New N- and O-arylations with phenylboronic acids and cupric acetate
D. M. T. Chan, K. L. Monaco, R.-P. Wang, M. P. Winteres, Tetrahedron Lett., 1998, 39, 2933-2936.

New aryl/heteroaryl C-N bond cross-coupling reactions via arylboronic acid/cupric acetate arylation
P. Y. S. Lam, C. G. Clark, S. Saubern, J. Adams, M. P. Winters, D. M. T. Chan, A. Combs, Tetrahedron Lett., 1998, 39, 2941-2944.

Comparison of Copper(II) Acetate Promoted N-Arylation of 5,5-Dimethyl Hydantoin and Other Imides with Triarylbismuthanes and Aryl Boronic Acids
H. M. Hügel, C. J. Rix, K. Fleck, Synlett, 2006, 2290-2292.