Ruthenium-catalyzed alkyne annulations with substituted 1H-pyrazoles by C-H/N-H bond functionalizations

Org Lett. 2012 Dec 21;14(24):6318-21. doi: 10.1021/ol303083n. Epub 2012 Dec 12.

Abstract

Cationic ruthenium(II) complexes allowed for highly efficient oxidative annulations of aryl- and alkyl-substituted alkynes by 5-aryl-1H-pyrazoles. The C-H/N-H bond functionalization strategy furthermore proved applicable to the high-yielding activation of heteroaryl as well as alkenyl C-H bonds.