New Method toward "Holy Grail of Chemistry"

Peking University, Oct. 12, 2010: C-H bond activation is a popular field that has been fast developing recently. The C-H bond s direct reaction of functional groups has various advantages, and the research of it is very challenging, which wins the conquering of it the title Holy Grail of Chemistry, while attracting more and more scientists attention.

The united aromatic compound is an important structural unit prevalent in natural products and molecule drugs. Among all the organic synthesis methods, the most efficient way to construct the united aromatic compounds is transition metal catalyzed cross-coupling reaction. The strategy at present is to substitute C-H bond for carbon-metal bond or carbon halogen bond in traditional coupling reaction, namely, cross-coupling reaction starting from general aromatic. During the past decade, great progress has shown in the classical C-H bond activation catalyzed by precious metals, but still, the remnant of poisonous precious metals and the high cost linger as difficulties to overcome. Lately, C-H bond activation catalyzed by cheap and easy-to-get common transition metal, even that which needs no catalysis, stands out as a dominance in further development within this field, which while facing great challenge and carrying strategic importance, will be of value in both the development of the theory of organic chemistry and the application of the chemical industry.

In the past year, Shi Zhangjie, professor of PKU College of Chemistry and Molecular Engineering, and his team underwent a systematic study on the C-H bond activation catalyzed by common transition metals (iron, cobalt, etc.) and the coupling reaction of aryl halides, during the process of which they found out the bond activation of aryl hydrocarbon products catalyzed by organic molecules phenanthroline derivatives. They also succeed in the coupling reaction of phenanthroline for aryl halides (bromide and iodide) and general aromatic, so that united aromatic compounds were more effectively constructed. Besides, they discovered that benzo chromene molecules could be made with a high yield by the appliance of coupling reaction in the molecular system. That provides a new, efficient, and economic way to synthesis various heteroatom polycyclic compounds. Research on relevant mechanism proves that reaction is a brand new process of C-H band activation, which is different from any classical mechanism of C-H bond activation catalyzed by transition metals, and meanwhile it solves the synthesis problem of heavy metals.

The research is published in Nature Chemistry (C.-L. Sun, H. Li, D.-G. Yu, M. Yu, X. Zhou, X.-Y. Lu, K. Huang, S.-F. Zheng, B.-J. Li, Z.-J. Shi. An efficient organocatalytic method for constructing biaryls through aromatic C-H activation. Nat. Chem. Online).

Translated by: ZHAO Ning

Edited by: Jacques

Source: PKU News (Chinese)