Synthesis 2010(24): 4154-4168  
DOI: 10.1055/s-0030-1258322
FEATUREARTICLE
© Georg Thieme Verlag Stuttgart ˙ New York

Palladium-Catalyzed Coupling Reaction of α-Diazocarbonyl Compounds with Aromatic Boronic Acids or Halides

Cheng Peng, Guobin Yan, Yan Wang, Yubo Jiang, Yan Zhang, Jianbo Wang*
Beijing National Laboratory of Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, P. R. of China
Fax: +86(10)62751708; e-Mail: wangjb@pku.edu.cn;
Further Information

Publication History

Received 6 September 2010
Publication Date:
15 November 2010 (online)

Abstract

Efficient palladium-catalyzed cross-coupling reactions of α-diazocarbonyl compounds and arylboronic acids or aryl halides have been developed. The reaction proceeds smoothly for a range of diazo compounds, boronic acids, and halides. The coupling reaction conditions tolerate various substituents on the aromatic rings of the substrates, such as chloro, fluoro, acyl, oxo, ester, and nitro groups. This coupling reaction constitutes a novel access to α-aryl-substituted α,β-unsaturated carbonyl compounds. Mechanistically, palladium-carbene is supposed to be the key intermediate; its formation is followed by migratory insertion of an aryl group to the carbenic carbon of the palladium-carbene complex and subsequent β-hydride elimination. Kinetic isotope effect (KIE) data measured for intra- and intermolecular competition experiments suggest that β-hydride elimination is not involved in the rate-determining step.